[gcc r15-1254] libstdc++: Optimize std::is_nothrow_invocable compilation performance

[Ken Matsui]

https://gcc.gnu.org/g:3060e9230264d60be349414285c361b7d32f233c

commit r15-1254-g3060e9230264d60be349414285c361b7d32f233c
Author: Ken Matsui <kmatsui@gcc.gnu.org>
Date:   Wed Feb 21 00:49:10 2024 -0800

    libstdc++: Optimize std::is_nothrow_invocable compilation performance
    
    This patch optimizes the compilation performance of
    std::is_nothrow_invocable by dispatching to the new
    __is_nothrow_invocable built-in trait.
    
    libstdc++-v3/ChangeLog:
    
            * include/std/type_traits (is_nothrow_invocable): Use
            __is_nothrow_invocable built-in trait.
            * testsuite/20_util/is_nothrow_invocable/incomplete_args_neg.cc:
            Handle the new error from __is_nothrow_invocable.
            * testsuite/20_util/is_nothrow_invocable/incomplete_neg.cc:
            Likewise.
    
    Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>
    Reviewed-by: Patrick Palka <ppalka@redhat.com>
    Reviewed-by: Jonathan Wakely <jwakely@redhat.com>

Diff:
---
 libstdc++-v3/include/std/type_traits                                  | 4 ++++
 .../testsuite/20_util/is_nothrow_invocable/incomplete_args_neg.cc     | 1 +
 libstdc++-v3/testsuite/20_util/is_nothrow_invocable/incomplete_neg.cc | 1 +
 3 files changed, 6 insertions(+)

diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits
index fcaff88c1932..8c8219b2697c 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -3231,8 +3231,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   /// std::is_nothrow_invocable
   template<typename _Fn, typename... _ArgTypes>
     struct is_nothrow_invocable
+#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_nothrow_invocable)
+    : public __bool_constant<__is_nothrow_invocable(_Fn, _ArgTypes...)>
+#else
     : __and_<__is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>,
 	     __call_is_nothrow_<_Fn, _ArgTypes...>>::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_nothrow_invocable/incomplete_args_neg.cc b/libstdc++-v3/testsuite/20_util/is_nothrow_invocable/incomplete_args_neg.cc
index 3c225883eaf2..3f8542dd366d 100644
--- a/libstdc++-v3/testsuite/20_util/is_nothrow_invocable/incomplete_args_neg.cc
+++ b/libstdc++-v3/testsuite/20_util/is_nothrow_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_nothrow_invocable/incomplete_neg.cc b/libstdc++-v3/testsuite/20_util/is_nothrow_invocable/incomplete_neg.cc
index 5a728bfa03ba..d3bdf08448b5 100644
--- a/libstdc++-v3/testsuite/20_util/is_nothrow_invocable/incomplete_neg.cc
+++ b/libstdc++-v3/testsuite/20_util/is_nothrow_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>