From: Xeonacid Date: Tue, 1 Sep 2026 18:23:56 +0800 Subject: Fix compilation and tests with C++20 (#64) GCC 16 defaults to C++20, which breaks BRiAl in two places. std::accumulate now invokes the binary operation as binary_op(std::move(acc), *i). AddEliminationDegree::operator() took a non-const size_type& that cannot bind to that rvalue. Take the accumulator by value and return the updated count instead. The numeric result is unchanged. operator==(bool, const BoolePolynomial&) is implemented as `return (rhs == lhs)`. In C++20 that expression also considers the reversed candidate, which is this same function, so the comparison recurses instead of calling BoolePolynomial::operator==(constant_type). The same issue applies to operator!=. Call the member operators directly. This keeps the existing semantics and unbreaks tests such as `true == BoolePolynomial(true, ring)`. --- libbrial/include/polybori/BoolePolynomial.h | 4 ++-- libbrial/src/BoolePolynomial.cc | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/libbrial/include/polybori/BoolePolynomial.h b/libbrial/include/polybori/BoolePolynomial.h index 2f5f35f8..96a68938 100644 --- a/libbrial/include/polybori/BoolePolynomial.h +++ b/libbrial/include/polybori/BoolePolynomial.h @@ -578,14 +578,14 @@ operator%(const BoolePolynomial& lhs, const RHSType& rhs){ inline BoolePolynomial::bool_type operator==(BoolePolynomial::bool_type lhs, const BoolePolynomial& rhs) { - return (rhs == lhs); + return rhs.operator==(lhs); } /// Nonquality check (with constant lhs) inline BoolePolynomial::bool_type operator!=(BoolePolynomial::bool_type lhs, const BoolePolynomial& rhs) { - return (rhs != lhs); + return rhs.operator!=(lhs); } /// Stream output operator diff --git a/libbrial/src/BoolePolynomial.cc b/libbrial/src/BoolePolynomial.cc index 8878354a..05e4d844 100644 --- a/libbrial/src/BoolePolynomial.cc +++ b/libbrial/src/BoolePolynomial.cc @@ -773,7 +773,7 @@ public: AddEliminationDegree(size_type min): m_min(min) {} - size_type& operator()(size_type& rhs, size_type lhs) { + size_type operator()(size_type rhs, size_type lhs) const { ++rhs; if (lhs > m_min) rhs += (lhs - m_min);