math_compat.h

#ifndef __math_compat_h
#define __math_compat_h

/* Define isnan and isinf on Windows/MSVC */

#ifndef HAVE_DECL_ISNAN
# ifdef HAVE_DECL__ISNAN
#include <float.h>
#define isnan(x) _isnan(x)
# endif
#endif

#ifndef HAVE_DECL_ISINF
# ifdef HAVE_DECL__FINITE
#include <float.h>
#define isinf(x) (!_finite(x))
# endif
#endif

#ifndef HAVE_DECL_NAN
#error This platform does not have nan()
#endif

#ifndef HAVE_DECL_INFINITY
#error This platform does not have INFINITY
#endif

#endif