func_isnan.m4 revision 53ecd51d974a9befce557f213de828c455d28500 
1#
2# This function determines if the isnan function is available on this
3# platform.
4#
5AC_DEFUN([AC_FUNC_ISNAN],[
6AC_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);}])
10AC_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);}])
14AC_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])
19