[sane-devel] sane.h misses extern "C"

[Mattias Ellert]

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Henning Meier-Geinitz wrote:
> Hi,
> 
>>Is there a good reason why the installed sane.h misses the usual
>>header lines needed for compilation with C++?
> 
> Well, it's a C and not a C++ header and these #ifdefs are ugly :-)

If you put them in the header file you only need them once. Since they 
are not in the header files you have to do

extern "C" {
#include <sane/sane.h>
}

in every c++ file. I think this is more "ugly". Having the extern 
declaration in one single place (i.e. in the header file) makes so much 
more sense than having to put in in every single file where you include it.

You don't have to do this kind of hack for normal system header files. 
Almost all other header files have the extern "C" declaration (or the 
equivalent __BEGIN_DECLS __END_DECLS pair).

> Isn't it a better solution to use the extern "C" when including the
> file in the C++ .C code if you really want to use sane.h in C++? Or do
> we get trouble this way because it includes the structs?

I think having them in the header file is "the better solution".

>>May I just commit them to CVS?

I would say YES.

> Please wait some time before doing that. Maybe someone else can tell
> us real reasons not to use the extern "C" stuff.
> 
> Bye,
>   Henning

	Mattias
-- 
________________________________________________________________________

mattias.ellert@tsl.uu.se                           tel: +46 18 471 32 58
http://www.tsl.uu.se/~ellert/                      fax: +46 18 471 35 13
________________________________________________________________________

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