Tested x86_64-linux. Pushed to trunk, backport to gcc-13 needed too.
-- >8 --
The new __is_convertible built-in should only be used after checking
that it's supported.
libstdc++-v3/ChangeLog:
PR libstdc++/113241
* include/std/type_traits (is_convertible_v): Guard use of
built-in with preprocessor check.
---
libstdc++-v3/include/std/type_traits | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/libstdc++-v3/include/std/type_traits
b/libstdc++-v3/include/std/type_traits
index a71162b33ec..3b1b419bbbb 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -3477,8 +3477,13 @@ template <typename _Tp>
#endif
template <typename _Base, typename _Derived>
inline constexpr bool is_base_of_v = __is_base_of(_Base, _Derived);
+#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_convertible)
template <typename _From, typename _To>
inline constexpr bool is_convertible_v = __is_convertible(_From, _To);
+#else
+template <typename _From, typename _To>
+ inline constexpr bool is_convertible_v = is_convertible<_From, _To>::value;
+#endif
template<typename _Fn, typename... _Args>
inline constexpr bool is_invocable_v = is_invocable<_Fn, _Args...>::value;
template<typename _Fn, typename... _Args>
--
2.43.0
