This patch optimizes the compilation performance of std::is_unsigned by dispatching to the new __is_unsigned built-in trait.
libstdc++-v3/ChangeLog: * include/std/type_traits (is_unsigned): Use __is_unsigned built-in trait. (is_unsigned_v): Likewise. Signed-off-by: Ken Matsui <kmat...@gcc.gnu.org> --- libstdc++-v3/include/std/type_traits | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits index 6294f5af533..4bcfb1389e3 100644 --- a/libstdc++-v3/include/std/type_traits +++ b/libstdc++-v3/include/std/type_traits @@ -987,10 +987,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { }; /// is_unsigned +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_unsigned) + template<typename _Tp> + struct is_unsigned + : public __bool_constant<__is_unsigned(_Tp)> + { }; +#else template<typename _Tp> struct is_unsigned : public __and_<is_arithmetic<_Tp>, __not_<is_signed<_Tp>>>::type { }; +#endif /// @cond undocumented template<typename _Tp, typename _Up = _Tp&&> @@ -3413,8 +3420,14 @@ template <typename _Tp> template <typename _Tp> inline constexpr bool is_signed_v = is_signed<_Tp>::value; + +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_unsigned) +template <typename _Tp> + inline constexpr bool is_unsigned_v = __is_unsigned(_Tp); +#else template <typename _Tp> inline constexpr bool is_unsigned_v = is_unsigned<_Tp>::value; +#endif template <typename _Tp, typename... _Args> inline constexpr bool is_constructible_v = __is_constructible(_Tp, _Args...); -- 2.43.0