dnl Available from the GNU Autoconf Macro Archive at:
dnl http://www.gnu.org/software/ac-archive/htmldoc/ac_cxx_rtti.html
dnl
AC_DEFUN([AC_CXX_RTTI],
[AC_CACHE_CHECK(whether the compiler supports Run-Time Type Identification,
ac_cv_cxx_rtti,
[AC_LANG_SAVE
 AC_LANG_CPLUSPLUS
 AC_TRY_COMPILE([#include <typeinfo>
class Base { public :
             Base () {}
             virtual int f () { return 0; }
           };
class Derived : public Base { public :
                              Derived () {}
                              virtual int f () { return 1; }
                            };
],[Derived d;
Base *ptr = &d;
return typeid (*ptr) == typeid (Derived);
],
 ac_cv_cxx_rtti=yes, ac_cv_cxx_rtti=no)
 AC_LANG_RESTORE
])
if test "$ac_cv_cxx_rtti" = yes; then
  AC_DEFINE(HAVE_RTTI,,
            [define if the compiler supports Run-Time Type Identification])
fi
])