AC_CXX_MUTABLE
, 
, 

2004年02月04日

Todd Veldhuizen Luc Maisonobe <luc@spaceroots.org>

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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 allows modifying class data members flagged with the mutable keyword even in const objects (for example in the body of a const member function), define HAVE_MUTABLE.

AC_DEFUN([AC_CXX_MUTABLE],
[AC_CACHE_CHECK(whether the compiler supports the mutable keyword,
ac_cv_cxx_mutable,
[AC_LANG_SAVE
 AC_LANG_CPLUSPLUS
 AC_TRY_COMPILE([
class A { mutable int i;
 public:
 int f (int n) const { i = n; return i; }
 };
],[A a; return a.f (1);],
 ac_cv_cxx_mutable=yes, ac_cv_cxx_mutable=no)
 AC_LANG_RESTORE
])
if test "$ac_cv_cxx_mutable" = yes; then
 AC_DEFINE(HAVE_MUTABLE,,[define if the compiler supports the mutable keyword])
fi
])