1# Checks whether the compiler implements namespaces 2AC_DEFUN([AC_CXX_NAMESPACES], 3 [AC_CACHE_CHECK(whether the compiler implements namespaces, 4 ac_cv_cxx_namespaces, 5 [AC_LANG_SAVE 6 AC_LANG_CPLUSPLUS 7 AC_TRY_COMPILE([namespace Outer { 8 namespace Inner { int i = 0; }}], 9 [using namespace Outer::Inner; return i;], 10 ac_cv_cxx_namespaces=yes, 11 ac_cv_cxx_namespaces=no) 12 AC_LANG_RESTORE]) 13 if test "$ac_cv_cxx_namespaces" = yes; then 14 AC_DEFINE(HAVE_NAMESPACES, 1, [define if the compiler implements namespaces]) 15 fi]) 16