##### http://autoconf-archive.cryp.to/ac_cxx_have_complex_math1.html
#
# SYNOPSIS
#
#   AC_CXX_HAVE_COMPLEX_MATH1
#
# DESCRIPTION
#
#   If the compiler has the complex math functions cos, cosh, exp, log,
#   pow, sin, sinh, sqrt, tan and tanh, define HAVE_COMPLEX_MATH1.
#
# LAST MODIFICATION
#
#   2004-02-04
#
# COPYLEFT
#
#   Copyright (c) 2004 Todd Veldhuizen
#   Copyright (c) 2004 Luc Maisonobe <luc@spaceroots.org>
#
#   Copying and distribution of this file, with or without
#   modification, are permitted in any medium without royalty provided
#   the copyright notice and this notice are preserved.

AC_DEFUN([AC_CXX_HAVE_COMPLEX_MATH1],
[AC_CACHE_CHECK(whether the compiler has complex math functions,
ac_cv_cxx_have_complex_math1,
[AC_REQUIRE([AC_CXX_NAMESPACES])
 AC_LANG_SAVE
 AC_LANG_CPLUSPLUS
 ac_save_LIBS="$LIBS"
 LIBS="$LIBS -lm"
 AC_TRY_LINK([#include <complex>
#ifdef HAVE_NAMESPACES
using namespace std;
#endif],[complex<double> x(1.0, 1.0), y(1.0, 1.0);
cos(x); cosh(x); exp(x); log(x); pow(x,1); pow(x,double(2.0));
pow(x, y); pow(double(2.0), x); sin(x); sinh(x); sqrt(x); tan(x); tanh(x);
return 0;],
 ac_cv_cxx_have_complex_math1=yes, ac_cv_cxx_have_complex_math1=no)
 LIBS="$ac_save_LIBS"
 AC_LANG_RESTORE
])
if test "$ac_cv_cxx_have_complex_math1" = yes; then
  AC_DEFINE(HAVE_COMPLEX_MATH1,,[define if the compiler has complex math functions])
fi
])