# We check what namespace stl code like vector expects to be executed in

AC_DEFUN([AC_CXX_STL_NAMESPACE],

  [AC_CACHE_CHECK(

      what namespace STL code is in,

      ac_cv_cxx_stl_namespace,

      [AC_REQUIRE([AC_CXX_NAMESPACES])

      AC_LANG_SAVE

      AC_LANG_CPLUSPLUS

      AC_TRY_COMPILE([#include <vector>],

                     [vector<int> t; return 0;],

                     ac_cv_cxx_stl_namespace=none)

      AC_TRY_COMPILE([#include <vector>],

                     [std::vector<int> t; return 0;],

                     ac_cv_cxx_stl_namespace=std)

      AC_LANG_RESTORE])

   if test "$ac_cv_cxx_stl_namespace" = none; then

      AC_DEFINE(STL_NAMESPACE,,

                [the namespace where STL code like vector<> is defined])

   fi

   if test "$ac_cv_cxx_stl_namespace" = std; then

      AC_DEFINE(STL_NAMESPACE,std,

                [the namespace where STL code like vector<> is defined])

   fi

])