[geos-devel] GCC 6 build error

[Mateusz Loskot]

On 2 March 2016 at 17:13, Sandro Santilli <strk at keybit.net> wrote:
>
> This is the snippet, in configure.ac, to look for it:
>
>   AC_LANG_PUSH([C++])
>   AC_CACHE_CHECK([for isnan], ac_cv_isnan,
>    [AC_TRY_LINK([#include <cmath>],
>    [double x; int y; y = isnan(x);],

I presume the test fails because it does not look for the function
inside std [1], but assumes nan is in global namespace.
I presume, it's especially the case for C++11 compilers.

[1] http://en.cppreference.com/w/cpp/numeric/math/isnan

Best regards,
-- 
Mateusz Łoskot, http://mateusz.loskot.net