On Wed, 29 Jan 2025 at 18:55, Patrick Palka wrote:
>
> Tested on x86_64-pc-linux-gnu, I suppose this is stage 1 material?
Yes, I think so, since it could impact C++17 programs.
OK for trunk as soon as stage 1 opens though, thanks.
>
> -- >8 --
>
> As a follow-up to r15-1253 and r15-1254.
>
> libstdc++-v3/ChangeLog:
>
> * include/std/type_traits (__is_invocable): Define in terms of
> corresponding builtin if available.
> (__is_nothrow_invocable): Likewise.
> (is_invocable_v): Likewise.
> (is_nothrow_invocable_v): Likewise.
> ---
> libstdc++-v3/include/std/type_traits | 19 ++++++++++++++++++-
> 1 file changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/libstdc++-v3/include/std/type_traits
> b/libstdc++-v3/include/std/type_traits
> index 33892818257..f576d5b1426 100644
> --- a/libstdc++-v3/include/std/type_traits
> +++ b/libstdc++-v3/include/std/type_traits
> @@ -3211,7 +3211,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>
> template<typename _Fn, typename... _ArgTypes>
> struct __is_invocable
> +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_invocable)
> + : __bool_constant<__is_invocable(_Fn, _ArgTypes...)>
> +#else
> : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
> +#endif
> { };
>
> template<typename _Fn, typename _Tp, typename... _Args>
> @@ -3262,8 +3266,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> // __is_nothrow_invocable (std::is_nothrow_invocable for C++11)
> template<typename _Fn, typename... _Args>
> struct __is_nothrow_invocable
> +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_nothrow_invocable)
> + : __bool_constant<__is_nothrow_invocable(_Fn, _Args...)>
> +#else
> : __and_<__is_invocable<_Fn, _Args...>,
> __call_is_nothrow_<_Fn, _Args...>>::type
> +#endif
> { };
>
> #pragma GCC diagnostic push
> @@ -3702,10 +3710,19 @@ 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;
> + inline constexpr bool is_invocable_v
> +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_invocable)
> + = __is_invocable(_Fn, _Args...);
> +#else
> + = is_invocable<_Fn, _Args...>::value;
> +#endif
> template<typename _Fn, typename... _Args>
> inline constexpr bool is_nothrow_invocable_v
> +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_nothrow_invocable)
> + = __is_nothrow_invocable(_Fn, _Args...);
> +#else
> = is_nothrow_invocable<_Fn, _Args...>::value;
> +#endif
> template<typename _Ret, typename _Fn, typename... _Args>
> inline constexpr bool is_invocable_r_v
> = is_invocable_r<_Ret, _Fn, _Args...>::value;
> --
> 2.48.1.131.gda898a5c64
>
