AC_CXX_ENUM_COMPUTATIONS
, 
, 

2004-02-04

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 handle computations inside an enum, define HAVE_ENUM_COMPUTATIONS.

AC_DEFUN([AC_CXX_ENUM_COMPUTATIONS],
[AC_CACHE_CHECK(whether the compiler handle computations inside an enum,
ac_cv_cxx_enum_computations,
[AC_LANG_SAVE
 AC_LANG_CPLUSPLUS
 AC_TRY_COMPILE([
struct A { enum { a = 5, b = 7, c = 2 }; };
struct B { enum { a = 1, b = 6, c = 9 }; };
template<class T1, class T2> struct Z
{ enum { a = (T1::a > T2::a) ? T1::a : T2::b,
         b = T1::b + T2::b,
         c = (T1::c * T2::c + T2::a + T1::a)
       };
};],[
return (((int)Z<A,B>::a == 5)
     && ((int)Z<A,B>::b == 13)
     && ((int)Z<A,B>::c == 24)) ? 0 : 1;],
 ac_cv_cxx_enum_computations=yes, ac_cv_cxx_enum_computations=no)
 AC_LANG_RESTORE
])
if test "$ac_cv_cxx_enum_computations" = yes; then
  AC_DEFINE(HAVE_ENUM_COMPUTATIONS,,
            [define if the compiler handle computations inside an enum])
fi
])