AC_DEFINE([USE_LIBCPP], [1], [Define to 1 if we are using libc++.])
fi
+AC_CACHE_CHECK(
+ [for c++11 atomic support without GNU Atomic library],
+ [folly_cv_lib_libatomic],
+ [AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM[
+ #include <atomic>
+ int main() {
+ struct Test { int val; };
+ std::atomic<Test> s;
+ s.is_lock_free();
+ }
+ ]],
+ [folly_cv_lib_libatomic=yes],
+ [folly_cv_lib_libatomic=no])])
+
+if test "$folly_cv_lib_libatomic" = no; then
+ AC_HAVE_LIBRARY([atomic],[],[AC_MSG_ERROR(
+ [Please install the GNU Atomic library])])
+fi
+
AC_CACHE_CHECK(
[for usable std::is_trivially_copyable],
[folly_cv_decl_std_is_trivially_copyable],