@@ -1069,7 +1069,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// 2328. Rvalue stream extraction should use perfect forwarding
// 1203. More useful rvalue stream insertion
-#if __cpp_lib_concepts
+#if __cpp_concepts >= 201907L
template<typename _Is, typename _Tp>
requires __derived_from_ios_base<_Is>
&& requires (_Is& __is, _Tp&& __t) { __is >> std::forward<_Tp>(__t); }
@@ -763,7 +763,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 1203. More useful rvalue stream insertion
-#if __cpp_lib_concepts
+#if __cpp_concepts >= 201907L
// Use concepts if possible because they're cheaper to evaluate.
template<typename _Tp>
concept __derived_from_ios_base = is_class_v<_Tp>