AC_CXX_TEMPLATE_QUALIFIED_RETURN_TYPE
,
,
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 template-qualified return types, define
HAVE_TEMPLATE_QUALIFIED_RETURN_TYPE.
AC_DEFUN([AC_CXX_TEMPLATE_QUALIFIED_RETURN_TYPE],
[AC_CACHE_CHECK(whether the compiler supports template-qualified return types,
ac_cv_cxx_template_qualified_return_type,
[AC_REQUIRE([AC_CXX_TYPENAME])
AC_LANG_SAVE
AC_LANG_CPLUSPLUS
AC_TRY_COMPILE([
#ifndef HAVE_TYPENAME
#define typename
#endif
template<class X, class Y> struct promote_trait { typedef X T; };
template<> struct promote_trait<int, float> { typedef float T; };
template<class T> class A { public : A () {} };
template<class X, class Y>
A<typename promote_trait<X,Y>::T> operator+ (const A<X>&, const A<Y>&)
{ return A<typename promote_trait<X,Y>::T>(); }
],[A<int> x; A<float> y; A<float> z = x + y; return 0;],
ac_cv_cxx_template_qualified_return_type=yes, ac_cv_cxx_template_qualified_return_type=no)
AC_LANG_RESTORE
])
if test "$ac_cv_cxx_template_qualified_return_type" = yes; then
AC_DEFINE(HAVE_TEMPLATE_QUALIFIED_RETURN_TYPE,,
[define if the compiler supports template-qualified return types])
fi
])