Bug#868974: roboptim-core: FTBFS: terminal-color.hh:40:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')

Wed Jul 19 19:47:45 UTC 2017

Source: roboptim-core
Version: 2.0-7.1
Severity: serious
Tags: buster sid
User: debian-qa at lists.debian.org
Usertags: qa-ftbfs-20170719 qa-ftbfs
Justification: FTBFS on amd64

Hi,

During a rebuild of all packages in sid, your package failed to build on
amd64.

Relevant part (hopefully):
> cd /<<PKGBUILDDIR>>/obj-x86_64-linux-gnu/src && /usr/bin/c++   -Droboptim_core_EXPORTS -I/<<PKGBUILDDIR>>/obj-x86_64-linux-gnu -I/<<PKGBUILDDIR>>/obj-x86_64-linux-gnu/include -I/<<PKGBUILDDIR>>/include -isystem /usr/include/eigen3  -g -O2 -fdebug-prefix-map=/<<PKGBUILDDIR>>=. -specs=/usr/share/dpkg/no-pie-compile.specs -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -fvisibility=hidden -Wdate-time -D_FORTIFY_SOURCE=2 -Werror  -pedantic -Wno-long-long -Wall -Wextra -Wcast-align -Wcast-qual -Wformat -Wwrite-strings -Wconversion -fPIC    -I/usr/include/eigen3 -o CMakeFiles/roboptim-core.dir/solver.cc.o -c /<<PKGBUILDDIR>>/src/solver.cc
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh: In function 'std::ostream& roboptim::fg::reset(std::ostream&)':
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:216:5: note: candidate: template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:216:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:216:5: note: candidate: template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:216:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: error: no match for 'operator!=' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: candidate: operator!=(int, int) <built-in>
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1894:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1894:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:293:5: note: candidate: template<class _Val> bool std::operator!=(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator!=(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:293:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:486:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const _Tp&, const std::complex<_Tp>&)
>      operator!=(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:486:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:481:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const _Tp&)
>      operator!=(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:481:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:476:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:476:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator!=(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:285:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:285:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:278:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:278:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator!=(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2217:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2217:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2211:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2211:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1335:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1335:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1367:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator!=(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator!=(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1367:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:246:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator!=(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator!=(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator!=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:334:5: note: candidate: template<class _Val> bool std::operator!=(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator!=(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:334:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note: candidate: template<class _CharT, class _Traits> bool std::operator!=(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:323:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_condition&)
>    operator!=(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:323:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:319:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_code&)
>    operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:319:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:315:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_condition&)
>    operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:315:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:311:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_code&)
>    operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:311:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5137:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5125:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5112:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5112:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:164:5: note: candidate: template<class _Tp> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:164:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:158:5: note: candidate: template<class _T1, class _T2> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator!=(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:158:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator!=(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator!=(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator!=(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator!=(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:448:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator!=(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:448:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:221:5: note: candidate: template<class _StateT> bool std::operator!=(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:221:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: error: no match for 'operator!=' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: candidate: operator!=(int, int) <built-in>
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1894:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1894:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:293:5: note: candidate: template<class _Val> bool std::operator!=(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator!=(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:293:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:486:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const _Tp&, const std::complex<_Tp>&)
>      operator!=(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:486:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:481:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const _Tp&)
>      operator!=(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:481:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:476:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:476:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator!=(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:285:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:285:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:278:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:278:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator!=(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2217:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2217:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2211:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2211:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1335:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1335:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1367:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator!=(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator!=(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1367:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:246:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator!=(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator!=(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator!=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:334:5: note: candidate: template<class _Val> bool std::operator!=(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator!=(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:334:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note: candidate: template<class _CharT, class _Traits> bool std::operator!=(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:323:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_condition&)
>    operator!=(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:323:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:319:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_code&)
>    operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:319:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:315:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_condition&)
>    operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:315:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:311:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_code&)
>    operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:311:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5137:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5125:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5112:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5112:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:164:5: note: candidate: template<class _Tp> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:164:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:158:5: note: candidate: template<class _T1, class _T2> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator!=(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:158:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator!=(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator!=(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator!=(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator!=(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:448:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator!=(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:448:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:221:5: note: candidate: template<class _StateT> bool std::operator!=(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:221:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh: In function 'std::ostream& roboptim::fg::red(std::ostream&)':
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:216:5: note: candidate: template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:216:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:216:5: note: candidate: template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:216:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: error: no match for 'operator!=' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: candidate: operator!=(int, int) <built-in>
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1894:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1894:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:293:5: note: candidate: template<class _Val> bool std::operator!=(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator!=(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:293:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:486:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const _Tp&, const std::complex<_Tp>&)
>      operator!=(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:486:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:481:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const _Tp&)
>      operator!=(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:481:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:476:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:476:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator!=(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:285:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:285:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:278:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:278:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator!=(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2217:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2217:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2211:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2211:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1335:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1335:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1367:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator!=(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator!=(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1367:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:246:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator!=(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator!=(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator!=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:334:5: note: candidate: template<class _Val> bool std::operator!=(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator!=(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:334:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note: candidate: template<class _CharT, class _Traits> bool std::operator!=(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:323:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_condition&)
>    operator!=(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:323:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:319:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_code&)
>    operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:319:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:315:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_condition&)
>    operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:315:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:311:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_code&)
>    operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:311:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5137:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5125:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5112:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5112:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:164:5: note: candidate: template<class _Tp> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:164:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:158:5: note: candidate: template<class _T1, class _T2> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator!=(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:158:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator!=(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator!=(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator!=(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator!=(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:448:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator!=(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:448:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:221:5: note: candidate: template<class _StateT> bool std::operator!=(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:221:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: error: no match for 'operator!=' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: candidate: operator!=(int, int) <built-in>
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1894:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1894:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:293:5: note: candidate: template<class _Val> bool std::operator!=(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator!=(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:293:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:486:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const _Tp&, const std::complex<_Tp>&)
>      operator!=(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:486:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:481:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const _Tp&)
>      operator!=(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:481:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:476:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:476:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator!=(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:285:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:285:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:278:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:278:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator!=(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2217:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2217:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2211:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2211:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1335:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1335:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1367:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator!=(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator!=(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1367:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:246:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator!=(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator!=(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator!=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:334:5: note: candidate: template<class _Val> bool std::operator!=(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator!=(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:334:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note: candidate: template<class _CharT, class _Traits> bool std::operator!=(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:323:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_condition&)
>    operator!=(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:323:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:319:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_code&)
>    operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:319:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:315:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_condition&)
>    operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:315:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:311:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_code&)
>    operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:311:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5137:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5125:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5112:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5112:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:164:5: note: candidate: template<class _Tp> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:164:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:158:5: note: candidate: template<class _T1, class _T2> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator!=(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:158:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator!=(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator!=(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator!=(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator!=(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:448:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator!=(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:448:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:221:5: note: candidate: template<class _StateT> bool std::operator!=(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:221:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh: In function 'std::ostream& roboptim::fg::green(std::ostream&)':
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:216:5: note: candidate: template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:216:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:216:5: note: candidate: template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:216:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: error: no match for 'operator!=' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: candidate: operator!=(int, int) <built-in>
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1894:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1894:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:293:5: note: candidate: template<class _Val> bool std::operator!=(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator!=(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:293:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:486:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const _Tp&, const std::complex<_Tp>&)
>      operator!=(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:486:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:481:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const _Tp&)
>      operator!=(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:481:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:476:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:476:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator!=(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:285:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:285:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:278:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:278:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator!=(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2217:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2217:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2211:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2211:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1335:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1335:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1367:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator!=(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator!=(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1367:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:246:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator!=(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator!=(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator!=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:334:5: note: candidate: template<class _Val> bool std::operator!=(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator!=(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:334:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note: candidate: template<class _CharT, class _Traits> bool std::operator!=(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:323:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_condition&)
>    operator!=(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:323:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:319:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_code&)
>    operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:319:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:315:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_condition&)
>    operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:315:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:311:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_code&)
>    operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:311:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5137:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5125:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5112:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5112:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:164:5: note: candidate: template<class _Tp> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:164:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:158:5: note: candidate: template<class _T1, class _T2> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator!=(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:158:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator!=(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator!=(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator!=(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator!=(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:448:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator!=(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:448:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:221:5: note: candidate: template<class _StateT> bool std::operator!=(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:221:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: error: no match for 'operator!=' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: candidate: operator!=(int, int) <built-in>
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1894:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1894:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:293:5: note: candidate: template<class _Val> bool std::operator!=(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator!=(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:293:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:486:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const _Tp&, const std::complex<_Tp>&)
>      operator!=(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:486:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:481:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const _Tp&)
>      operator!=(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:481:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:476:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:476:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator!=(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:285:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:285:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:278:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:278:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator!=(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2217:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2217:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2211:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2211:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1335:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1335:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1367:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator!=(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator!=(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1367:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:246:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator!=(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator!=(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator!=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:334:5: note: candidate: template<class _Val> bool std::operator!=(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator!=(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:334:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note: candidate: template<class _CharT, class _Traits> bool std::operator!=(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:323:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_condition&)
>    operator!=(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:323:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:319:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_code&)
>    operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:319:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:315:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_condition&)
>    operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:315:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:311:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_code&)
>    operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:311:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5137:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5125:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5112:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5112:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:164:5: note: candidate: template<class _Tp> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:164:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:158:5: note: candidate: template<class _T1, class _T2> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator!=(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:158:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator!=(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator!=(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator!=(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator!=(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:448:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator!=(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:448:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:221:5: note: candidate: template<class _StateT> bool std::operator!=(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:221:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh: In function 'std::ostream& roboptim::fg::yellow(std::ostream&)':
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:216:5: note: candidate: template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:216:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:216:5: note: candidate: template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:216:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: error: no match for 'operator!=' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: candidate: operator!=(int, int) <built-in>
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1894:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1894:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:293:5: note: candidate: template<class _Val> bool std::operator!=(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator!=(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:293:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:486:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const _Tp&, const std::complex<_Tp>&)
>      operator!=(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:486:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:481:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const _Tp&)
>      operator!=(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:481:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:476:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:476:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator!=(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:285:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:285:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:278:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:278:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator!=(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2217:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2217:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2211:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2211:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1335:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1335:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1367:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator!=(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator!=(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1367:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:246:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator!=(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator!=(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator!=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:334:5: note: candidate: template<class _Val> bool std::operator!=(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator!=(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:334:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note: candidate: template<class _CharT, class _Traits> bool std::operator!=(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:323:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_condition&)
>    operator!=(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:323:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:319:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_code&)
>    operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:319:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:315:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_condition&)
>    operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:315:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:311:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_code&)
>    operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:311:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5137:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5125:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5112:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5112:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:164:5: note: candidate: template<class _Tp> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:164:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:158:5: note: candidate: template<class _T1, class _T2> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator!=(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:158:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator!=(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator!=(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator!=(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator!=(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:448:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator!=(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:448:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:221:5: note: candidate: template<class _StateT> bool std::operator!=(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:221:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: error: no match for 'operator!=' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: candidate: operator!=(int, int) <built-in>
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1894:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1894:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:293:5: note: candidate: template<class _Val> bool std::operator!=(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator!=(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:293:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:486:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const _Tp&, const std::complex<_Tp>&)
>      operator!=(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:486:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:481:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const _Tp&)
>      operator!=(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:481:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:476:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:476:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator!=(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:285:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:285:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:278:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:278:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator!=(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2217:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2217:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2211:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2211:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1335:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1335:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1367:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator!=(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator!=(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1367:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:246:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator!=(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator!=(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator!=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:334:5: note: candidate: template<class _Val> bool std::operator!=(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator!=(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:334:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note: candidate: template<class _CharT, class _Traits> bool std::operator!=(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:323:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_condition&)
>    operator!=(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:323:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:319:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_code&)
>    operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:319:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:315:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_condition&)
>    operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:315:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:311:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_code&)
>    operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:311:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5137:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5125:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5112:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5112:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:164:5: note: candidate: template<class _Tp> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:164:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:158:5: note: candidate: template<class _T1, class _T2> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator!=(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:158:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator!=(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator!=(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator!=(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator!=(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:448:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator!=(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:448:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:221:5: note: candidate: template<class _StateT> bool std::operator!=(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:221:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh: In function 'std::ostream& roboptim::fg::blue(std::ostream&)':
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:216:5: note: candidate: template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:216:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:216:5: note: candidate: template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:216:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: error: no match for 'operator!=' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: candidate: operator!=(int, int) <built-in>
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1894:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1894:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:293:5: note: candidate: template<class _Val> bool std::operator!=(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator!=(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:293:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:486:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const _Tp&, const std::complex<_Tp>&)
>      operator!=(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:486:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:481:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const _Tp&)
>      operator!=(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:481:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:476:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:476:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator!=(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:285:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:285:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:278:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:278:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator!=(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2217:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2217:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2211:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2211:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1335:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1335:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1367:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator!=(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator!=(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1367:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:246:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator!=(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator!=(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator!=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:334:5: note: candidate: template<class _Val> bool std::operator!=(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator!=(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:334:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note: candidate: template<class _CharT, class _Traits> bool std::operator!=(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:323:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_condition&)
>    operator!=(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:323:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:319:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_code&)
>    operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:319:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:315:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_condition&)
>    operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:315:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:311:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_code&)
>    operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:311:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5137:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5125:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5112:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5112:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:164:5: note: candidate: template<class _Tp> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:164:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:158:5: note: candidate: template<class _T1, class _T2> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator!=(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:158:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator!=(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator!=(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator!=(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator!=(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:448:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator!=(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:448:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:221:5: note: candidate: template<class _StateT> bool std::operator!=(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:221:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: error: no match for 'operator!=' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: candidate: operator!=(int, int) <built-in>
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1894:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1894:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:293:5: note: candidate: template<class _Val> bool std::operator!=(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator!=(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:293:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:486:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const _Tp&, const std::complex<_Tp>&)
>      operator!=(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:486:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:481:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const _Tp&)
>      operator!=(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:481:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:476:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:476:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator!=(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:285:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:285:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:278:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:278:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator!=(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2217:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2217:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2211:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2211:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1335:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1335:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1367:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator!=(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator!=(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1367:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:246:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator!=(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator!=(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator!=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:334:5: note: candidate: template<class _Val> bool std::operator!=(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator!=(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:334:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note: candidate: template<class _CharT, class _Traits> bool std::operator!=(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:323:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_condition&)
>    operator!=(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:323:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:319:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_code&)
>    operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:319:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:315:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_condition&)
>    operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:315:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:311:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_code&)
>    operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:311:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5137:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5125:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5112:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5112:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:164:5: note: candidate: template<class _Tp> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:164:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:158:5: note: candidate: template<class _T1, class _T2> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator!=(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:158:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator!=(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator!=(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator!=(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator!=(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:448:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator!=(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:448:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:221:5: note: candidate: template<class _StateT> bool std::operator!=(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:221:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh: In function 'std::ostream& roboptim::fg::orange(std::ostream&)':
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:216:5: note: candidate: template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:216:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:216:5: note: candidate: template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:216:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: error: no match for 'operator!=' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: candidate: operator!=(int, int) <built-in>
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1894:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1894:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:293:5: note: candidate: template<class _Val> bool std::operator!=(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator!=(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:293:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:486:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const _Tp&, const std::complex<_Tp>&)
>      operator!=(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:486:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:481:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const _Tp&)
>      operator!=(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:481:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:476:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:476:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator!=(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:285:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:285:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:278:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:278:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh: In function 'std::ostream& roboptim::fg::reset(std::ostream&)':
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator!=(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2217:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2217:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2211:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2211:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1335:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1335:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1367:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator!=(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator!=(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1367:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:246:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator!=(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator!=(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator!=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:334:5: note: candidate: template<class _Val> bool std::operator!=(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator!=(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:334:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note: candidate: template<class _CharT, class _Traits> bool std::operator!=(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:323:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_condition&)
>    operator!=(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:323:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:319:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_code&)
>    operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:319:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:315:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_condition&)
>    operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:315:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:311:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_code&)
>    operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:311:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5137:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr.h:347:5: note: candidate: template<class _Tp> bool std::operator==(std::nullptr_t, const std::shared_ptr<_Tp1>&)
>      operator==(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:347:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr.h:342:5: note: candidate: template<class _Tp> bool std::operator==(const std::shared_ptr<_Tp1>&, std::nullptr_t)
>      operator==(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:342:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr.h:336:5: note: candidate: template<class _Tp1, class _Tp2> bool std::operator==(const std::shared_ptr<_Tp1>&, const std::shared_ptr<_Tp2>&)
>      operator==(const shared_ptr<_Tp1>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:336:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5125:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5125:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr_base.h:1197:5: note: candidate: template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator==(std::nullptr_t, const std::__shared_ptr<_Tp, _Lp>&)
>      operator==(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1197:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr_base.h:1192:5: note: candidate: template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator==(const std::__shared_ptr<_Tp, _Lp>&, std::nullptr_t)
>      operator==(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1192:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr_base.h:1186:5: note: candidate: template<class _Tp1, class _Tp2, __gnu_cxx::_Lock_policy _Lp> bool std::operator==(const std::__shared_ptr<_Tp1, _Lp>&, const std::__shared_ptr<_Tp2, _Lp>&)
>      operator==(const __shared_ptr<_Tp1, _Lp>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1186:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp1, _Lp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5112:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5112:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:79:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:164:5: note: candidate: template<class _Tp> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:164:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:79:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/variant/detail/move.hpp:23,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:158:5: note: candidate: template<class _T1, class _T2> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator!=(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:158:5: note:   template argument deduction/substitution failed:
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator!=(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator!=(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note:   template argument deduction/substitution failed:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator!=(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator!=(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:448:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator!=(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:448:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/postypes.h:216:5: note: candidate: template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:216:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:221:5: note: candidate: template<class _StateT> bool std::operator!=(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:221:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: error: no match for 'operator!=' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: candidate: operator!=(int, int) <built-in>
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr.h:347:5: note: candidate: template<class _Tp> bool std::operator==(std::nullptr_t, const std::shared_ptr<_Tp1>&)
>      operator==(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:347:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1894:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1894:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr.h:342:5: note: candidate: template<class _Tp> bool std::operator==(const std::shared_ptr<_Tp1>&, std::nullptr_t)
>      operator==(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:342:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr.h:336:5: note: candidate: template<class _Tp1, class _Tp2> bool std::operator==(const std::shared_ptr<_Tp1>&, const std::shared_ptr<_Tp2>&)
>      operator==(const shared_ptr<_Tp1>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:336:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_list.h:293:5: note: candidate: template<class _Val> bool std::operator!=(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator!=(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:293:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr_base.h:1197:5: note: candidate: template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator==(std::nullptr_t, const std::__shared_ptr<_Tp, _Lp>&)
>      operator==(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
>      ^~~~~~~~
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1197:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr_base.h:1192:5: note: candidate: template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator==(const std::__shared_ptr<_Tp, _Lp>&, std::nullptr_t)
>      operator==(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1192:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr_base.h:1186:5: note: candidate: template<class _Tp1, class _Tp2, __gnu_cxx::_Lock_policy _Lp> bool std::operator==(const std::__shared_ptr<_Tp1, _Lp>&, const std::__shared_ptr<_Tp2, _Lp>&)
>      operator==(const __shared_ptr<_Tp1, _Lp>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1186:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp1, _Lp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:79:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:486:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const _Tp&, const std::complex<_Tp>&)
>      operator!=(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:486:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:79:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:481:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const _Tp&)
>      operator!=(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:481:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/variant/detail/move.hpp:23,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/complex:476:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> /usr/include/c++/6/complex:476:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator!=(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:285:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:285:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:278:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:278:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/detail/iterator.hpp:11,
>                  from /usr/include/boost/iterator/iterator_traits.hpp:8,
>                  from /usr/include/boost/range/iterator_range_core.hpp:26,
>                  from /usr/include/boost/algorithm/string/replace.hpp:16,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator!=(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_conv.h:41:0,
>                  from /usr/include/c++/6/locale:43,
>                  from /usr/include/c++/6/iomanip:43,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:21,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/result.hh:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:27,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2217:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2217:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/postypes.h:216:5: note: candidate: template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:216:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/boost/utility/compare_pointees.hpp:15:0,
>                  from /usr/include/boost/optional/optional.hpp:48,
>                  from /usr/include/boost/optional.hpp:15,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver-error.hh:25,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:20:
> /usr/include/c++/6/functional:2211:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2211:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: error: no match for 'operator!=' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: candidate: operator!=(int, int) <built-in>
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_list.h:1894:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1894:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_list.h:293:5: note: candidate: template<class _Val> bool std::operator!=(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator!=(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:293:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1335:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1335:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/complex:486:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const _Tp&, const std::complex<_Tp>&)
>      operator!=(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:486:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/complex:481:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const _Tp&)
>      operator!=(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:481:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/complex:476:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:476:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/tuple:1367:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator!=(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator!=(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1367:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator!=(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_deque.h:285:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:285:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_deque.h:278:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:278:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr.h:363:5: note: candidate: template<class _Tp> bool std::operator!=(std::nullptr_t, const std::shared_ptr<_Tp1>&)
>      operator!=(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:363:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr.h:358:5: note: candidate: template<class _Tp> bool std::operator!=(const std::shared_ptr<_Tp1>&, std::nullptr_t)
>      operator!=(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:358:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr.h:352:5: note: candidate: template<class _Tp1, class _Tp2> bool std::operator!=(const std::shared_ptr<_Tp1>&, const std::shared_ptr<_Tp2>&)
>      operator!=(const shared_ptr<_Tp1>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:352:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr_base.h:1213:5: note: candidate: template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator!=(std::nullptr_t, const std::__shared_ptr<_Tp, _Lp>&)
>      operator!=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1213:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr_base.h:1208:5: note: candidate: template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator!=(const std::__shared_ptr<_Tp, _Lp>&, std::nullptr_t)
>      operator!=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1208:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/array:246:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator!=(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr_base.h:1202:5: note: candidate: template<class _Tp1, class _Tp2, __gnu_cxx::_Lock_policy _Lp> bool std::operator!=(const std::__shared_ptr<_Tp1, _Lp>&, const std::__shared_ptr<_Tp2, _Lp>&)
>      operator!=(const __shared_ptr<_Tp1, _Lp>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/array:246:5: note:   template argument deduction/substitution failed:
> /usr/include/c++/6/bits/shared_ptr_base.h:1202:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp1, _Lp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator!=(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator!=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:334:5: note: candidate: template<class _Val> bool std::operator!=(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator!=(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:334:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note: candidate: template<class _CharT, class _Traits> bool std::operator!=(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/system_error:323:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_condition&)
>    operator!=(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:323:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:319:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_code&)
>    operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:79:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/functional:2217:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2217:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:79:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/functional:2211:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2211:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/variant/detail/move.hpp:23,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator!=(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1335:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1335:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> /usr/include/c++/6/system_error:319:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:315:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_condition&)
>    operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:315:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:311:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_code&)
>    operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:311:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5137:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5125:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5112:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5112:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:164:5: note: candidate: template<class _Tp> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:164:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/allocator.h:158:5: note: candidate: template<class _T1, class _T2> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator!=(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:158:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/tuple:1367:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator!=(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator!=(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1367:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/array:246:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator!=(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator!=(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator!=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:334:5: note: candidate: template<class _Val> bool std::operator!=(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator!=(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:334:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note: candidate: template<class _CharT, class _Traits> bool std::operator!=(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator!=(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator!=(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator!=(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator!=(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:448:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator!=(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:448:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver-error.cc:18:
> /usr/include/c++/6/bits/postypes.h:221:5: note: candidate: template<class _StateT> bool std::operator!=(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:221:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/src/solver-error.cc:21:0:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/system_error:323:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_condition&)
>    operator!=(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:323:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:319:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_code&)
>    operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:319:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:315:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_condition&)
>    operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:315:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:311:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_code&)
>    operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:311:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5137:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5125:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5112:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5112:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/allocator.h:164:5: note: candidate: template<class _Tp> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:164:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/allocator.h:158:5: note: candidate: template<class _T1, class _T2> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator!=(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:158:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator!=(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator!=(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator!=(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator!=(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:448:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator!=(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:448:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/postypes.h:221:5: note: candidate: template<class _StateT> bool std::operator!=(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:221:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: error: no match for 'operator!=' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: candidate: operator!=(int, int) <built-in>
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o != std::cout && o != std::cerr)  \
>                              ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:31: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_list.h:1894:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1894:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_list.h:293:5: note: candidate: template<class _Val> bool std::operator!=(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator!=(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:293:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/complex:486:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const _Tp&, const std::complex<_Tp>&)
>      operator!=(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:486:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/complex:481:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const _Tp&)
>      operator!=(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:481:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/complex:476:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:476:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator!=(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_deque.h:285:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:285:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_deque.h:278:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:278:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr.h:363:5: note: candidate: template<class _Tp> bool std::operator!=(std::nullptr_t, const std::shared_ptr<_Tp1>&)
>      operator!=(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:363:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr.h:358:5: note: candidate: template<class _Tp> bool std::operator!=(const std::shared_ptr<_Tp1>&, std::nullptr_t)
>      operator!=(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:358:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr.h:352:5: note: candidate: template<class _Tp1, class _Tp2> bool std::operator!=(const std::shared_ptr<_Tp1>&, const std::shared_ptr<_Tp2>&)
>      operator!=(const shared_ptr<_Tp1>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:352:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr_base.h:1213:5: note: candidate: template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator!=(std::nullptr_t, const std::__shared_ptr<_Tp, _Lp>&)
>      operator!=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1213:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr_base.h:1208:5: note: candidate: template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator!=(const std::__shared_ptr<_Tp, _Lp>&, std::nullptr_t)
>      operator!=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1208:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr_base.h:1202:5: note: candidate: template<class _Tp1, class _Tp2, __gnu_cxx::_Lock_policy _Lp> bool std::operator!=(const std::__shared_ptr<_Tp1, _Lp>&, const std::__shared_ptr<_Tp2, _Lp>&)
>      operator!=(const __shared_ptr<_Tp1, _Lp>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1202:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp1, _Lp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:678:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note: candidate: template<class _Tp, class _Dp> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:673:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator!=(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator!=(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:667:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/memory:79:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/functional:2217:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2217:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/memory:79:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/functional:2211:5: note: candidate: template<class _Res, class ... _Args> bool std::operator!=(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2211:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/variant/detail/move.hpp:23,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator!=(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:1000:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1335:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator!=(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1335:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/tuple:1367:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator!=(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator!=(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1367:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/array:246:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator!=(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator!=(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator!=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1302:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:334:5: note: candidate: template<class _Val> bool std::operator!=(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator!=(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:334:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1533:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note: candidate: template<class _CharT, class _Traits> bool std::operator!=(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:210:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/system_error:323:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_condition&)
>    operator!=(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:323:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:319:3: note: candidate: bool std::operator!=(const std::error_condition&, const std::error_code&)
>    operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:319:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:315:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_condition&)
>    operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:315:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:311:3: note: candidate: bool std::operator!=(const std::error_code&, const std::error_code&)
>    operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:311:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5137:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5137:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5125:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5112:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5112:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/allocator.h:164:5: note: candidate: template<class _Tp> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:164:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/allocator.h:158:5: note: candidate: template<class _T1, class _T2> bool std::operator!=(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator!=(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:158:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator!=(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1131:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator!=(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1125:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator!=(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:361:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note: candidate: template<class _Iterator> bool std::operator!=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator!=(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:304:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:448:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator!=(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:448:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/postypes.h:221:5: note: candidate: template<class _StateT> bool std::operator!=(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:221:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:39: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                                        ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh: In function 'std::ostream& roboptim::fg::red(std::ostream&)':
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh: In function 'std::ostream& roboptim::fg::reset(std::ostream&)':
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr.h:347:5: note: candidate: template<class _Tp> bool std::operator==(std::nullptr_t, const std::shared_ptr<_Tp1>&)
>      operator==(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:347:5: note:   template argument deduction/substitution failed:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>              ^~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr.h:342:5: note: candidate: template<class _Tp> bool std::operator==(const std::shared_ptr<_Tp1>&, std::nullptr_t)
>      operator==(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:342:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr.h:336:5: note: candidate: template<class _Tp1, class _Tp2> bool std::operator==(const std::shared_ptr<_Tp1>&, const std::shared_ptr<_Tp2>&)
>      operator==(const shared_ptr<_Tp1>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:336:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr_base.h:1197:5: note: candidate: template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator==(std::nullptr_t, const std::__shared_ptr<_Tp, _Lp>&)
>      operator==(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> /usr/include/c++/6/bits/shared_ptr_base.h:1197:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr_base.h:1192:5: note: candidate: template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator==(const std::__shared_ptr<_Tp, _Lp>&, std::nullptr_t)
>      operator==(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1192:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr.h:347:5: note: candidate: template<class _Tp> bool std::operator==(std::nullptr_t, const std::shared_ptr<_Tp1>&)
>      operator==(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:347:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr.h:342:5: note: candidate: template<class _Tp> bool std::operator==(const std::shared_ptr<_Tp1>&, std::nullptr_t)
>      operator==(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:342:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr.h:336:5: note: candidate: template<class _Tp1, class _Tp2> bool std::operator==(const std::shared_ptr<_Tp1>&, const std::shared_ptr<_Tp2>&)
>      operator==(const shared_ptr<_Tp1>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:336:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr_base.h:1197:5: note: candidate: template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator==(std::nullptr_t, const std::__shared_ptr<_Tp, _Lp>&)
>      operator==(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1197:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr_base.h:1192:5: note: candidate: template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator==(const std::__shared_ptr<_Tp, _Lp>&, std::nullptr_t)
>      operator==(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1192:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr_base.h:1186:5: note: candidate: template<class _Tp1, class _Tp2, __gnu_cxx::_Lock_policy _Lp> bool std::operator==(const std::__shared_ptr<_Tp1, _Lp>&, const std::__shared_ptr<_Tp2, _Lp>&)
>      operator==(const __shared_ptr<_Tp1, _Lp>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1186:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp1, _Lp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/shared_ptr_base.h:1186:5: note: candidate: template<class _Tp1, class _Tp2, __gnu_cxx::_Lock_policy _Lp> bool std::operator==(const std::__shared_ptr<_Tp1, _Lp>&, const std::__shared_ptr<_Tp2, _Lp>&)
>      operator==(const __shared_ptr<_Tp1, _Lp>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1186:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp1, _Lp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:79:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:79:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/variant/detail/move.hpp:23,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:79:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/postypes.h:216:5: note: candidate: template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/postypes.h:216:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:79:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: error: no match for 'operator==' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: candidate: operator==(int, int) <built-in>
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>              ^~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/variant/detail/move.hpp:23,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:27,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1853:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1853:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stl_list.h:287:5: note: candidate: template<class _Val> bool std::operator==(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator==(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:287:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/complex:468:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const _Tp&, const std::complex<_Tp>&)
>      operator==(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:468:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/complex:463:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const _Tp&)
>      operator==(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:463:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/complex:458:5: note: candidate: template<class _Tp> constexpr bool std::operator==(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:458:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator==(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2220:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:272:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:272:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:265:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator==(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:265:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr.h:347:5: note: candidate: template<class _Tp> bool std::operator==(std::nullptr_t, const std::shared_ptr<_Tp1>&)
>      operator==(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:347:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr.h:342:5: note: candidate: template<class _Tp> bool std::operator==(const std::shared_ptr<_Tp1>&, std::nullptr_t)
>      operator==(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:342:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr.h:336:5: note: candidate: template<class _Tp1, class _Tp2> bool std::operator==(const std::shared_ptr<_Tp1>&, const std::shared_ptr<_Tp2>&)
>      operator==(const shared_ptr<_Tp1>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:336:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr_base.h:1197:5: note: candidate: template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator==(std::nullptr_t, const std::__shared_ptr<_Tp, _Lp>&)
>      operator==(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1197:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr_base.h:1192:5: note: candidate: template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator==(const std::__shared_ptr<_Tp, _Lp>&, std::nullptr_t)
>      operator==(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1192:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr_base.h:1186:5: note: candidate: template<class _Tp1, class _Tp2, __gnu_cxx::_Lock_policy _Lp> bool std::operator==(const std::__shared_ptr<_Tp1, _Lp>&, const std::__shared_ptr<_Tp2, _Lp>&)
>      operator==(const __shared_ptr<_Tp1, _Lp>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1186:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp1, _Lp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)
>      operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:661:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note: candidate: template<class _Tp, class _Dp> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)
>      operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:656:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:81:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note: candidate: template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator==(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)
>      operator==(const unique_ptr<_Tp, _Dp>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/unique_ptr.h:650:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:79:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/functional:2199:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(std::nullptr_t, const std::function<_Res(_ArgTypes ...)>&)
>      operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2199:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:79:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/functional:2193:5: note: candidate: template<class _Res, class ... _Args> bool std::operator==(const std::function<_Res(_ArgTypes ...)>&, std::nullptr_t)
>      operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/functional:2193:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::function<_Res(_ArgTypes ...)>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/iterator:66:0,
>                  from /usr/include/boost/variant/detail/move.hpp:23,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note: candidate: template<class _Tp, class _CharT, class _Traits, class _Dist> bool std::operator==(const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&, const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>&)
>      operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stream_iterator.h:130:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istream_iterator<_Tp, _CharT, _Traits, _Dist>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:62:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_multimap.h:976:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:61:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_map.h:1311:5: note: candidate: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
>      operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_map.h:1311:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> In file included from /usr/include/c++/6/bits/stl_map.h:63:0,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/tuple:1341:5: note: candidate: template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const std::tuple<_Args1 ...>&, const std::tuple<_Args2 ...>&)
>      operator==(const tuple<_TElements...>& __t,
>      ^~~~~~~~
> /usr/include/c++/6/tuple:1341:5: note:   template argument deduction/substitution failed:
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::tuple<_Args1 ...>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/tuple:39:0,
>                  from /usr/include/c++/6/bits/stl_map.h:63,
>                  from /usr/include/c++/6/map:61,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/array:241:5: note: candidate: template<class _Tp, long unsigned int _Nm> bool std::operator==(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
>      operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
>      ^~~~~~~~
> /usr/include/c++/6/array:241:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::array<_Tp, _Nm>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note: candidate: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator==(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
>      operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:1282:5: note:   template argument deduction/substitution failed:
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/map:60:0,
>                  from /usr/include/log4cxx/helpers/class.h:29,
>                  from /usr/include/log4cxx/helpers/object.h:22,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:29,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_tree.h:328:5: note: candidate: template<class _Val> bool std::operator==(const std::_Rb_tree_iterator<_Tp>&, const std::_Rb_tree_const_iterator<_Val>&)
>      operator==(const _Rb_tree_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_tree.h:328:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Rb_tree_iterator<_Tp>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/vector:64:0,
>                  from /usr/include/log4cxx/spi/appenderattachable.h:27,
>                  from /usr/include/log4cxx/helpers/appenderattachableimpl.h:27,
>                  from /usr/include/log4cxx/logger.h:26,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/debug.hh:20,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:55,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator==(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
>      operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_vector.h:1509:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::vector<_Tp, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
>                  from /usr/include/c++/6/bits/basic_ios.h:37,
>                  from /usr/include/c++/6/ios:44,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note: candidate: template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)
>      operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/streambuf_iterator.h:204:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/bits/ios_base.h:46:0,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/system_error:303:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_condition&)
>    operator==(const error_condition& __lhs,
>    ^~~~~~~~
> /usr/include/c++/6/system_error:303:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> /usr/include/c++/6/system_error:296:3: note: candidate: bool std::operator==(const std::error_condition&, const std::error_code&)
>    operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:296:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_condition&'
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> /usr/include/c++/6/system_error:289:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_condition&)
>    operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:289:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> /usr/include/c++/6/system_error:284:3: note: candidate: bool std::operator==(const std::error_code&, const std::error_code&)
>    operator==(const error_code& __lhs, const error_code& __rhs) noexcept
>    ^~~~~~~~
> /usr/include/c++/6/system_error:284:3: note:   no known conversion for argument 1 from 'std::ostream {aka std::basic_ostream<char>}' to 'const std::error_code&'
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5099:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5099:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5087:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const _CharT* __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5087:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5073:5: note: candidate: template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)
>      operator==(const basic_string<_CharT>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5073:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:52:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/basic_string.h:5065:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
>      operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
>      ^~~~~~~~
> /usr/include/c++/6/bits/basic_string.h:5065:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::pair<_T1, _T2>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/allocator.h:152:5: note: candidate: template<class _Tp> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_CharT>&)
>      operator==(const allocator<_Tp>&, const allocator<_Tp>&)
>      ^~~~~~~~
> In file included from /usr/include/c++/6/iosfwd:40:0,
>                  from /usr/include/c++/6/ios:38,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:18:
> /usr/include/c++/6/bits/postypes.h:216:5: note: candidate: template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)
>      operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:152:5: note:   template argument deduction/substitution failed:
> /usr/include/c++/6/bits/postypes.h:216:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::fpos<_StateT>'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:42:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cerr && !isatty (fileno (stderr))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: error: no match for 'operator!=' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'std::ostream {aka std::basic_ostream<char>}')
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: candidate: operator!=(int, int) <built-in>
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note:   no known conversion for argument 2 from 'std::ostream {aka std::basic_ostream<char>}' to 'int'
>        if (o != std::cout && o != std::cerr)  \
>            ~~^~~~
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:13: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>              ^~
> In file included from /usr/include/c++/6/string:41:0,
>                  from /usr/include/c++/6/bits/locale_classes.h:40,
>                  from /usr/include/c++/6/bits/ios_base.h:41,
>                  from /usr/include/c++/6/ios:42,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/allocator.h:146:5: note: candidate: template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)
>      operator==(const allocator<_T1>&, const allocator<_T2>&)
>      ^~~~~~~~
> /usr/include/c++/6/bits/allocator.h:146:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stl_list.h:1894:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)
>      operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:1894:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::allocator<_CharT>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/list:63:0,
>                  from /usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IncompleteCholesky.h:15,
>                  from /usr/include/eigen3/Eigen/IterativeLinearSolvers:44,
>                  from /usr/include/eigen3/Eigen/Sparse:33,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:36,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stl_list.h:293:5: note: candidate: template<class _Val> bool std::operator!=(const std::_List_iterator<_Tp>&, const std::_List_const_iterator<_Tp>&)
>      operator!=(const _List_iterator<_Val>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_list.h:293:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_List_iterator<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note: candidate: template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)
>      operator==(const move_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:1119:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/complex:486:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const _Tp&, const std::complex<_Tp>&)
>      operator!=(const _Tp& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:486:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/complex:481:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const _Tp&)
>      operator!=(const complex<_Tp>& __x, const _Tp& __y)
>      ^~~~~~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)
>      operator==(const move_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/complex:481:5: note:   template argument deduction/substitution failed:
> /usr/include/c++/6/bits/stl_iterator.h:1113:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/eigen3/Eigen/Core:80:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:34,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/complex:476:5: note: candidate: template<class _Tp> constexpr bool std::operator!=(const std::complex<_Tp>&, const std::complex<_Tp>&)
>      operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
>      ^~~~~~~~
> /usr/include/c++/6/complex:476:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::complex<_Tp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::move_iterator<_IteratorL>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note: candidate: template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
>      operator==(const reverse_iterator<_IteratorL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:349:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note: candidate: template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
>      operator==(const reverse_iterator<_Iterator>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_iterator.h:292:5: note:   template argument deduction/substitution failed:
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note: candidate: template<class _Tp, class _Alloc> bool std::operator!=(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)
>      operator!=(const deque<_Tp, _Alloc>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:2246:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::deque<_Tp, _Alloc>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:285:5: note: candidate: template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)
>      operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:285:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/deque:64:0,
>                  from /usr/include/boost/algorithm/string/find_format.hpp:14,
>                  from /usr/include/boost/algorithm/string/replace.hpp:22,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/function.hh:29,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/stl_deque.h:278:5: note: candidate: template<class _Tp, class _Ref, class _Ptr> bool std::operator!=(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)
>      operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
>      ^~~~~~~~
> /usr/include/c++/6/bits/stl_deque.h:278:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr.h:363:5: note: candidate: template<class _Tp> bool std::operator!=(std::nullptr_t, const std::shared_ptr<_Tp1>&)
>      operator!=(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:363:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr.h:358:5: note: candidate: template<class _Tp> bool std::operator!=(const std::shared_ptr<_Tp1>&, std::nullptr_t)
>      operator!=(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:358:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/memory:82:0,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr.h:352:5: note: candidate: template<class _Tp1, class _Tp2> bool std::operator!=(const std::shared_ptr<_Tp1>&, const std::shared_ptr<_Tp2>&)
>      operator!=(const shared_ptr<_Tp1>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr.h:352:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::shared_ptr<_Tp1>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/generic-solver.hh:33,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:22:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:40:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o == std::cout && !isatty (fileno (stdout))) \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr_base.h:1213:5: note: candidate: template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator!=(std::nullptr_t, const std::__shared_ptr<_Tp, _Lp>&)
>      operator!=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1213:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr_base.h:1208:5: note: candidate: template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator!=(const std::__shared_ptr<_Tp, _Lp>&, std::nullptr_t)
>      operator!=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1208:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0,
>                  from /usr/include/c++/6/bits/char_traits.h:39,
>                  from /usr/include/c++/6/ios:40,
>                  from /usr/include/c++/6/ostream:38,
>                  from /usr/include/c++/6/iostream:39,
>                  from /<<PKGBUILDDIR>>/src/debug.hh:23,
>                  from /<<PKGBUILDDIR>>/src/generic-solver.cc:18:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
>      operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
>      ^~~~~~~~
> In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
>                  from /usr/include/c++/6/memory:82,
>                  from /usr/include/boost/move/algorithm.hpp:33,
>                  from /usr/include/boost/move/move.hpp:32,
>                  from /usr/include/boost/variant/detail/move.hpp:28,
>                  from /usr/include/boost/variant/detail/initializer.hpp:23,
>                  from /usr/include/boost/variant/variant.hpp:30,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:29,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /usr/include/c++/6/bits/shared_ptr_base.h:1202:5: note: candidate: template<class _Tp1, class _Tp2, __gnu_cxx::_Lock_policy _Lp> bool std::operator!=(const std::__shared_ptr<_Tp1, _Lp>&, const std::__shared_ptr<_Tp2, _Lp>&)
>      operator!=(const __shared_ptr<_Tp1, _Lp>& __a,
>      ^~~~~~~~
> /usr/include/c++/6/bits/shared_ptr_base.h:1202:5: note:   template argument deduction/substitution failed:
> /usr/include/c++/6/bits/stl_pair.h:435:5: note:   template argument deduction/substitution failed:
> In file included from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hxx:29:0,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/problem.hh:484,
>                  from /<<PKGBUILDDIR>>/include/roboptim/core/solver.hh:34,
>                  from /<<PKGBUILDDIR>>/src/solver.cc:20:
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note:   'std::ostream {aka std::basic_ostream<char>}' is not derived from 'const std::__shared_ptr<_Tp1, _Lp>'
>        if (o != std::cout && o != std::cerr)  \
>                      ^
> /<<PKGBUILDDIR>>/include/roboptim/core/terminal-color.hh:44:21: note: in definition of macro 'ROBOPTIM_CORE_FILTER_TTY'
>        if (o != std::cout && o != std::cerr)  \
>                      ^~~~
> src/CMakeFiles/roboptim-core.dir/build.make:281: recipe for target 'src/CMakeFiles/roboptim-core.dir/solver-error.cc.o' failed
> make[3]: *** [src/CMakeFiles/roboptim-core.dir/solver-error.cc.o] Error 1

The full build log is available from:
   http://aws-logs.debian.net/2017/07/19/roboptim-core_2.0-7.1_unstable.log

A list of current common problems and possible solutions is available at
http://wiki.debian.org/qa.debian.org/FTBFS . You're welcome to contribute!

About the archive rebuild: The rebuild was done on EC2 VM instances from
Amazon Web Services, using a clean, minimal and up-to-date chroot. Every
failed build was retried once to eliminate random failures.