On Fri, Oct 20, 2023 at 12:22 PM Ken Matsui <kmat...@gcc.gnu.org> wrote:
>
> This patch optimizes the compilation performance of std::is_invocable
> by dispatching to the new __is_invocable built-in trait.
>
> libstdc++-v3/ChangeLog:
>
> * include/std/type_traits (is_invocable): Use __is_invocable
> built-in trait.
Nice! We should use the trait directly in is_invocable_v too.
> * testsuite/20_util/is_invocable/incomplete_args_neg.cc: Handle
> the new error from __is_invocable.
> * testsuite/20_util/is_invocable/incomplete_neg.cc: Likewise.
>
> Signed-off-by: Ken Matsui <kmat...@gcc.gnu.org>
> ---
> libstdc++-v3/include/std/type_traits | 6 ++++++
> .../testsuite/20_util/is_invocable/incomplete_args_neg.cc | 1 +
> .../testsuite/20_util/is_invocable/incomplete_neg.cc | 1 +
> 3 files changed, 8 insertions(+)
>
> diff --git a/libstdc++-v3/include/std/type_traits
> b/libstdc++-v3/include/std/type_traits
> index 75a94cb8d7e..91851b78c7e 100644
> --- a/libstdc++-v3/include/std/type_traits
> +++ b/libstdc++-v3/include/std/type_traits
> @@ -3167,9 +3167,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> using invoke_result_t = typename invoke_result<_Fn, _Args...>::type;
>
> /// std::is_invocable
> +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_invocable)
> + template<typename _Fn, typename... _ArgTypes>
> + struct is_invocable
> + : public __bool_constant<__is_invocable(_Fn, _ArgTypes...)>
> +#else
> template<typename _Fn, typename... _ArgTypes>
> struct is_invocable
> : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
> +#endif
> {
> static_assert(std::__is_complete_or_unbounded(__type_identity<_Fn>{}),
> "_Fn must be a complete class or an unbounded array");
> diff --git
> a/libstdc++-v3/testsuite/20_util/is_invocable/incomplete_args_neg.cc
> b/libstdc++-v3/testsuite/20_util/is_invocable/incomplete_args_neg.cc
> index 34d1d9431d1..3f9e5274f3c 100644
> --- a/libstdc++-v3/testsuite/20_util/is_invocable/incomplete_args_neg.cc
> +++ b/libstdc++-v3/testsuite/20_util/is_invocable/incomplete_args_neg.cc
> @@ -18,6 +18,7 @@
> // <http://www.gnu.org/licenses/>.
>
> // { dg-error "must be a complete class" "" { target *-*-* } 0 }
> +// { dg-prune-output "invalid use of incomplete type" }
>
> #include <type_traits>
>
> diff --git a/libstdc++-v3/testsuite/20_util/is_invocable/incomplete_neg.cc
> b/libstdc++-v3/testsuite/20_util/is_invocable/incomplete_neg.cc
> index e1e54d25ee5..92af48c48b6 100644
> --- a/libstdc++-v3/testsuite/20_util/is_invocable/incomplete_neg.cc
> +++ b/libstdc++-v3/testsuite/20_util/is_invocable/incomplete_neg.cc
> @@ -18,6 +18,7 @@
> // <http://www.gnu.org/licenses/>.
>
> // { dg-error "must be a complete class" "" { target *-*-* } 0 }
> +// { dg-prune-output "invalid use of incomplete type" }
>
> #include <type_traits>
>
> --
> 2.42.0
>
