autoconf/m4/func_isnan.m4

   1 #
   2 # This function determines if the isnan function is available on this
   3 # platform.
   4 #
   5 AC_DEFUN([AC_FUNC_ISNAN],[
   6 AC_SINGLE_CXX_CHECK([HAVE_ISNAN_IN_MATH_H],    [ac_cv_func_isnan_in_math_h],
   7                     [isnan], [<math.h>],
   8                     [#include <math.h>
   9                      int foo(float f) {return isnan(f);}])
  10 AC_SINGLE_CXX_CHECK([HAVE_ISNAN_IN_CMATH],     [ac_cv_func_isnan_in_cmath],
  11                     [isnan], [<cmath>],
  12                     [#include <cmath>
  13                      int foo(float f) {return isnan(f);}])
  14 AC_SINGLE_CXX_CHECK([HAVE_STD_ISNAN_IN_CMATH], [ac_cv_func_std_isnan_in_cmath],
  15                     [std::isnan], [<cmath>],
  16                     [#include <cmath>
  17                      using std::isnan; int foo(float f) {return isnan(f);}])
  18 ])