-#if (!defined(_LIBCPP_VERSION) || _LIBCPP_VERSION < 4000) && \
- !defined(FOLLY_SKIP_LIBCPP_4000_THROW_BACKPORTS)
-void __throw_length_error(const char* msg) {
+#if _LIBCPP_VERSION < 4000 && !FOLLY_SKIP_LIBCPP_4000_THROW_BACKPORTS
+void __throw_length_error(char const* msg) {