On Wed, 10 Jan 2024 at 19:48, Ken Matsui <kmat...@gcc.gnu.org> wrote:
>
> This patch optimizes the compilation performance of std::is_integral
> by dispatching to the new __is_integral built-in trait.
OK for trunk (if the new built-in gets approved).
>
> libstdc++-v3/ChangeLog:
>
> * include/std/type_traits (is_integral): Use __is_integral
> built-in trait.
> (is_integral_v): Likewise.
>
> Signed-off-by: Ken Matsui <kmat...@gcc.gnu.org>
> ---
> libstdc++-v3/include/std/type_traits | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/libstdc++-v3/include/std/type_traits
> b/libstdc++-v3/include/std/type_traits
> index 1cec0822b73..afa281d9cc4 100644
> --- a/libstdc++-v3/include/std/type_traits
> +++ b/libstdc++-v3/include/std/type_traits
> @@ -334,6 +334,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> struct is_void<const volatile void>
> : public true_type { };
>
> +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_integral)
> + /// is_integral
> + template<typename _Tp>
> + struct is_integral
> + : public __bool_constant<__is_integral(_Tp)>
> + { };
> +#else
> /// @cond undocumented
> template<typename>
> struct __is_integral_helper
> @@ -461,6 +468,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> struct is_integral
> : public __is_integral_helper<__remove_cv_t<_Tp>>::type
> { };
> +#endif
>
> /// @cond undocumented
> template<typename>
> @@ -3221,8 +3229,15 @@ template <typename _Tp>
> inline constexpr bool is_void_v = is_void<_Tp>::value;
> template <typename _Tp>
> inline constexpr bool is_null_pointer_v = is_null_pointer<_Tp>::value;
> +
> +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_integral)
> +template <typename _Tp>
> + inline constexpr bool is_integral_v = __is_integral(_Tp);
> +#else
> template <typename _Tp>
> inline constexpr bool is_integral_v = is_integral<_Tp>::value;
> +#endif
> +
> template <typename _Tp>
> inline constexpr bool is_floating_point_v = is_floating_point<_Tp>::value;
>
> --
> 2.43.0
>
