Todd Veldhuizen
Luc Maisonobe <luc@spaceroots.org>
AllPermissive
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. Users of this software should generally follow the
principles of the
MIT License includings its disclaimer.
cryp.to ac-archive's C++ Support (released)
If the compiler supports numeric traits promotions, define
HAVE_USE_NUMTRAIT.
AC_DEFUN([AC_CXX_USE_NUMTRAIT],
[AC_CACHE_CHECK(whether the compiler supports numeric traits promotions,
ac_cv_cxx_use_numtrait,
[AC_REQUIRE([AC_CXX_TYPENAME])
AC_LANG_SAVE
AC_LANG_CPLUSPLUS
AC_TRY_COMPILE([
#ifndef HAVE_TYPENAME
#define typename
#endif
template<class T_numtype> class SumType { public : typedef T_numtype T_sumtype; };
template<> class SumType<char> { public : typedef int T_sumtype; };
template<class T> class A {};
template<class T> A<typename SumType<T>::T_sumtype> sum(A<T>)
{ return A<typename SumType<T>::T_sumtype>(); }
],[A<float> x; sum(x); return 0;],
ac_cv_cxx_use_numtrait=yes, ac_cv_cxx_use_numtrait=no)
AC_LANG_RESTORE
])
if test "$ac_cv_cxx_use_numtrait" = yes; then
AC_DEFINE(HAVE_USE_NUMTRAIT,,[define if the compiler supports numeric traits promotions])
fi
])