# # Check for bidirectional iterator extension. This is modified from # http://www.gnu.org/software/ac-archive/htmldoc/ac_cxx_have_ext_hash_set.html # AC_DEFUN([AC_CXX_HAVE_BI_ITERATOR], [AC_CACHE_CHECK(whether the compiler has the bidirectional iterator, ac_cv_cxx_have_bi_iterator, [AC_REQUIRE([AC_CXX_NAMESPACES]) AC_LANG_PUSH([C++]) AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <iterator> #ifdef HAVE_NAMESPACES using namespace std; #endif]], [[bidirectional_iterator<int,int> t; return 0;]])],[ac_cv_cxx_have_bi_iterator=yes],[ac_cv_cxx_have_bi_iterator=no]) AC_LANG_POP([C++]) ]) if test "$ac_cv_cxx_have_bi_iterator" = yes then AC_DEFINE(HAVE_BI_ITERATOR,1,[Have bi-directional iterator]) else AC_DEFINE(HAVE_BI_ITERATOR,0,[Does not have bi-directional iterator]) fi ])