# platform.
#
AC_DEFUN([AC_FUNC_ISNAN],[
-AC_SINGLE_CXX_CHECK([HAVE_ISNAN_IN_MATH_H], [ac_cv_func_isnan_in_math_h],
+AC_SINGLE_CXX_CHECK([ac_cv_func_isnan_in_math_h],
[isnan], [<math.h>],
- [#include <math.h>
- int foo(float f) {return isnan(f);}])
-AC_SINGLE_CXX_CHECK([HAVE_ISNAN_IN_CMATH], [ac_cv_func_isnan_in_cmath],
+ [float f; isnan(f);])
+
+if test "$ac_cv_func_isnan_in_math_h" = "yes" ; then
+ AC_DEFINE([HAVE_ISNAN_IN_MATH_H],1,[Set to 1 if the isnan function is found in <math.h>])
+fi
+
+AC_SINGLE_CXX_CHECK([ac_cv_func_isnan_in_cmath],
[isnan], [<cmath>],
- [#include <cmath>
- int foo(float f) {return isnan(f);}])
-AC_SINGLE_CXX_CHECK([HAVE_STD_ISNAN_IN_CMATH], [ac_cv_func_std_isnan_in_cmath],
+ [float f; isnan(f);])
+if test "$ac_cv_func_isnan_in_cmath" = "yes" ; then
+ AC_DEFINE([HAVE_ISNAN_IN_CMATH],1,[Set to 1 if the isnan function is found in <cmath>])
+fi
+
+AC_SINGLE_CXX_CHECK([ac_cv_func_std_isnan_in_cmath],
[std::isnan], [<cmath>],
- [#include <cmath>
- using std::isnan; int foo(float f) {return isnan(f);}])
+ [float f; std::isnan(f);])
+if test "$ac_cv_func_std_isnan_in_cmath" = "yes" ; then
+ AC_DEFINE([HAVE_STD_ISNAN_IN_CMATH],1,[Set to 1 if the std::isnan function is found in <cmath>])
+fi
])