On Sun, 9 Jul 2023 at 09:50, Ken Matsui via Libstdc++
<libstd...@gcc.gnu.org> wrote:
>
> This patch lets libstdc++ use new built-in trait __is_signed.
>
> libstdc++-v3/ChangeLog:
>
> * include/std/type_traits (is_signed): Use __is_signed built-in trait.
> (is_signed_v): Likewise.
>
> Signed-off-by: Ken Matsui <kmat...@gcc.gnu.org>
OK for trunk after the front-end implementation of __is_signed is committed.
> ---
> libstdc++-v3/include/std/type_traits | 15 ++++++++++++++-
> 1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/libstdc++-v3/include/std/type_traits
> b/libstdc++-v3/include/std/type_traits
> index 0e7a9c9c7f3..23ab5a4b1e5 100644
> --- a/libstdc++-v3/include/std/type_traits
> +++ b/libstdc++-v3/include/std/type_traits
> @@ -865,6 +865,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> : public __bool_constant<__is_abstract(_Tp)>
> { };
>
> + /// is_signed
> +#if __has_builtin(__is_signed)
> + template<typename _Tp>
> + struct is_signed
> + : public __bool_constant<__is_signed(_Tp)>
> + { };
> +#else
> /// @cond undocumented
> template<typename _Tp,
> bool = is_arithmetic<_Tp>::value>
> @@ -877,11 +884,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> { };
> /// @endcond
>
> - /// is_signed
> template<typename _Tp>
> struct is_signed
> : public __is_signed_helper<_Tp>::type
> { };
> +#endif
>
> /// is_unsigned
> template<typename _Tp>
> @@ -3240,8 +3247,14 @@ template <typename _Tp>
> template <typename _Tp>
> inline constexpr bool is_final_v = __is_final(_Tp);
>
> +#if __has_builtin(__is_signed)
> +template <typename _Tp>
> + inline constexpr bool is_signed_v = __is_signed(_Tp);
> +#else
> template <typename _Tp>
> inline constexpr bool is_signed_v = is_signed<_Tp>::value;
> +#endif
> +
> template <typename _Tp>
> inline constexpr bool is_unsigned_v = is_unsigned<_Tp>::value;
>
> --
> 2.41.0
>
