[libcxx-commits] [libcxx] Speed up legacy (non-builtin) std::invoke() compile times by ~20%-45% (PR #213403)

via libcxx-commits libcxx-commits at lists.llvm.org
Sat Aug 1 18:58:30 PDT 2026


https://github.com/higher-performance updated https://github.com/llvm/llvm-project/pull/213403

>From e8bd10b1db03fcf796670174beb1f6b8a2a49652 Mon Sep 17 00:00:00 2001
From: higher-performance <higher.performance.github at gmail.com>
Date: Sat, 1 Aug 2026 00:40:29 -0400
Subject: [PATCH] Speed up legacy implementation of std::invoke() by 50%

---
 libcxx/include/__functional/invoke.h  |   4 +-
 libcxx/include/__type_traits/invoke.h | 335 +++++++++++---------------
 2 files changed, 148 insertions(+), 191 deletions(-)

diff --git a/libcxx/include/__functional/invoke.h b/libcxx/include/__functional/invoke.h
index f7d6a23a4e520..823c5c1532800 100644
--- a/libcxx/include/__functional/invoke.h
+++ b/libcxx/include/__functional/invoke.h
@@ -24,8 +24,8 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Fn, class... _Args>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 invoke_result_t<_Fn, _Args...>
-invoke(_Fn&& __f, _Args&&... __args) noexcept(is_nothrow_invocable_v<_Fn, _Args...>) {
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __sfinae_invoke_result_t<_Fn, _Args...>
+invoke(_Fn&& __f, _Args&&... __args) noexcept(__is_nothrow_invocable_v<_Fn, _Args...>) {
   return std::__invoke(std::forward<_Fn>(__f), std::forward<_Args>(__args)...);
 }
 
diff --git a/libcxx/include/__type_traits/invoke.h b/libcxx/include/__type_traits/invoke.h
index ba8202576593e..141fc0ae3a8bb 100644
--- a/libcxx/include/__type_traits/invoke.h
+++ b/libcxx/include/__type_traits/invoke.h
@@ -17,11 +17,15 @@
 #include <__type_traits/integral_constant.h>
 #include <__type_traits/is_base_of.h>
 #include <__type_traits/is_core_convertible.h>
+#include <__type_traits/is_function.h>
 #include <__type_traits/is_member_pointer.h>
 #include <__type_traits/is_reference_wrapper.h>
 #include <__type_traits/is_same.h>
 #include <__type_traits/is_void.h>
 #include <__type_traits/nat.h>
+#include <__type_traits/remove_cvref.h>
+#include <__type_traits/remove_reference.h>
+#include <__type_traits/type_identity.h>
 #include <__type_traits/void_t.h>
 #include <__utility/declval.h>
 #include <__utility/forward.h>
@@ -74,18 +78,15 @@ template <class, class... _Args>
 struct __invoke_result_impl {};
 
 template <class... _Args>
-struct __invoke_result_impl<__void_t<decltype(__builtin_invoke(std::declval<_Args>()...))>, _Args...> {
-  using type _LIBCPP_NODEBUG = decltype(__builtin_invoke(std::declval<_Args>()...));
-};
-
-template <class... _Args>
-using __invoke_result _LIBCPP_NODEBUG = __invoke_result_impl<void, _Args...>;
+using __sfinae_invoke_result_t _LIBCPP_NODEBUG = decltype(__builtin_invoke(std::declval<_Args>()...));
 
 template <class... _Args>
-using __invoke_result_t _LIBCPP_NODEBUG = typename __invoke_result<_Args...>::type;
+struct __invoke_result_impl<__void_t<__sfinae_invoke_result_t<_Args...> >, _Args...> {
+  using type _LIBCPP_NODEBUG = __sfinae_invoke_result_t<_Args...>;
+};
 
 template <class... _Args>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR __invoke_result_t<_Args...> __invoke(_Args&&... __args)
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR __sfinae_invoke_result_t<_Args...> __invoke(_Args&&... __args)
     _NOEXCEPT_(noexcept(__builtin_invoke(std::forward<_Args>(__args)...))) {
   return __builtin_invoke(std::forward<_Args>(__args)...);
 }
@@ -94,7 +95,7 @@ template <class _Void, class... _Args>
 inline const bool __is_invocable_impl = false;
 
 template <class... _Args>
-inline const bool __is_invocable_impl<__void_t<__invoke_result_t<_Args...> >, _Args...> = true;
+inline const bool __is_invocable_impl<__void_t<__sfinae_invoke_result_t<_Args...> >, _Args...> = true;
 
 template <class... _Args>
 inline const bool __is_invocable_v = __is_invocable_impl<void, _Args...>;
@@ -107,28 +108,29 @@ inline const bool __is_invocable_r_impl = false;
 
 template <class _Ret, class... _Args>
 inline const bool __is_invocable_r_impl<_Ret, true, _Args...> =
-    __is_core_convertible<__invoke_result_t<_Args...>, _Ret>::value || is_void<_Ret>::value;
+    __is_core_convertible<__sfinae_invoke_result_t<_Args...>, _Ret>::value || is_void<_Ret>::value;
 
 template <class _Ret, class... _Args>
 inline const bool __is_invocable_r_v = __is_invocable_r_impl<_Ret, __is_invocable_v<_Args...>, _Args...>;
 
-template <bool __is_invocable, class... _Args>
+template <class _Void, class... _Args>
 inline const bool __is_nothrow_invocable_impl = false;
 
 #  ifndef _LIBCPP_CXX03_LANG
 template <class... _Args>
-inline const bool __is_nothrow_invocable_impl<true, _Args...> = noexcept(__builtin_invoke(std::declval<_Args>()...));
+inline const bool
+    __is_nothrow_invocable_impl<__enable_if_t<noexcept(__builtin_invoke(std::declval<_Args>()...))>, _Args...> = true;
 #  endif
 
 template <class... _Args>
-inline const bool __is_nothrow_invocable_v = __is_nothrow_invocable_impl<__is_invocable_v<_Args...>, _Args...>;
+inline const bool __is_nothrow_invocable_v = __is_nothrow_invocable_impl<void, _Args...>;
 
 template <bool __is_invocable, class _Ret, class... _Args>
 inline const bool __is_nothrow_invocable_r_impl = false;
 
 template <class _Ret, class... _Args>
 inline const bool __is_nothrow_invocable_r_impl<true, _Ret, _Args...> =
-    __is_nothrow_core_convertible_v<__invoke_result_t<_Args...>, _Ret> || is_void<_Ret>::value;
+    __is_nothrow_core_convertible_v<__sfinae_invoke_result_t<_Args...>, _Ret> || is_void<_Ret>::value;
 
 template <class _Ret, class... _Args>
 inline const bool __is_nothrow_invocable_r_v =
@@ -136,224 +138,179 @@ inline const bool __is_nothrow_invocable_r_v =
 
 #else // __has_builtin(__builtin_invoke)
 
+template <class _Base, class _Derived>
+using __base_of _LIBCPP_NODEBUG =
+    __conditional_t< is_same<_Base, _Derived>::value, is_same<_Base, _Derived>, is_base_of<_Base, _Derived>>;
+
+template <class, class... _Args>
+struct __invoke_result_impl {};
+
 template <class _DecayedFp>
-struct __member_pointer_class_type {};
+struct __member_pointer_traits {};
 
 template <class _Ret, class _ClassType>
-struct __member_pointer_class_type<_Ret _ClassType::*> {
-  typedef _ClassType type;
+struct __member_pointer_traits<_Ret _ClassType::*> {
+  typedef _ClassType __class_type;
+  typedef _Ret __member_type;
+  typedef __member_pointer_traits __self;
 };
 
-template <class _Fp,
-          class _A0,
-          class _DecayFp = __decay_t<_Fp>,
-          class _DecayA0 = __decay_t<_A0>,
-          class _ClassT  = typename __member_pointer_class_type<_DecayFp>::type>
-using __enable_if_bullet1 _LIBCPP_NODEBUG =
-    __enable_if_t<is_member_function_pointer<_DecayFp>::value &&
-                  (is_same<_ClassT, _DecayA0>::value || is_base_of<_ClassT, _DecayA0>::value)>;
-
-template <class _Fp, class _A0, class _DecayFp = __decay_t<_Fp>, class _DecayA0 = __decay_t<_A0> >
-using __enable_if_bullet2 _LIBCPP_NODEBUG =
-    __enable_if_t<is_member_function_pointer<_DecayFp>::value && __is_reference_wrapper<_DecayA0>::value>;
-
-template <class _Fp,
-          class _A0,
-          class _DecayFp = __decay_t<_Fp>,
-          class _DecayA0 = __decay_t<_A0>,
-          class _ClassT  = typename __member_pointer_class_type<_DecayFp>::type>
-using __enable_if_bullet3 _LIBCPP_NODEBUG =
-    __enable_if_t<is_member_function_pointer<_DecayFp>::value &&
-                  !(is_same<_ClassT, _DecayA0>::value || is_base_of<_ClassT, _DecayA0>::value) &&
-                  !__is_reference_wrapper<_DecayA0>::value>;
-
-template <class _Fp,
-          class _A0,
-          class _DecayFp = __decay_t<_Fp>,
-          class _DecayA0 = __decay_t<_A0>,
-          class _ClassT  = typename __member_pointer_class_type<_DecayFp>::type>
-using __enable_if_bullet4 _LIBCPP_NODEBUG =
-    __enable_if_t<is_member_object_pointer<_DecayFp>::value &&
-                  (is_same<_ClassT, _DecayA0>::value || is_base_of<_ClassT, _DecayA0>::value)>;
-
-template <class _Fp, class _A0, class _DecayFp = __decay_t<_Fp>, class _DecayA0 = __decay_t<_A0> >
-using __enable_if_bullet5 _LIBCPP_NODEBUG =
-    __enable_if_t<is_member_object_pointer<_DecayFp>::value && __is_reference_wrapper<_DecayA0>::value>;
-
-template <class _Fp,
-          class _A0,
-          class _DecayFp = __decay_t<_Fp>,
-          class _DecayA0 = __decay_t<_A0>,
-          class _ClassT  = typename __member_pointer_class_type<_DecayFp>::type>
-using __enable_if_bullet6 _LIBCPP_NODEBUG =
-    __enable_if_t<is_member_object_pointer<_DecayFp>::value &&
-                  !(is_same<_ClassT, _DecayA0>::value || is_base_of<_ClassT, _DecayA0>::value) &&
-                  !__is_reference_wrapper<_DecayA0>::value>;
+#  define _LIBCPP_INLINE_EXPR(expr)                                                                                    \
+    _NOEXCEPT_(noexcept(expr))->decltype(expr) { return expr; }                                                        \
+    static_assert(true, "")
 
-// __invoke forward declarations
+// The _Kind is the bullet number in the standard
+template <unsigned _Kind>
+struct __invoker;
 
-// fall back - none of the bullets
+// __invoke forward declarations
 
-template <class... _Args>
-__nat __invoke(_Args&&... __args);
+template <class _Traits, class _A0, class _DecayA0 = __decay_t<_A0>, class _IsRefWrapper = __is_reference_wrapper<_DecayA0>>
+using __invoker_t _LIBCPP_NODEBUG = __invoker<
+    (!is_function<typename _Traits::__member_type>::value * 3) +
+    (!__conditional_t<_IsRefWrapper::value, false_type, __base_of<typename _Traits::__class_type, _DecayA0>>::value
+      << 1) +
+    !_IsRefWrapper::value>;
 
 // bullets 1, 2 and 3
 
-// clang-format off
-template <class _Fp, class _A0, class... _Args, class = __enable_if_bullet1<_Fp, _A0> >
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
-decltype((std::declval<_A0>().*std::declval<_Fp>())(std::declval<_Args>()...))
-__invoke(_Fp&& __f, _A0&& __a0, _Args&&... __args)
-    _NOEXCEPT_(noexcept((static_cast<_A0&&>(__a0).*__f)(static_cast<_Args&&>(__args)...)))
-               { return (static_cast<_A0&&>(__a0).*__f)(static_cast<_Args&&>(__args)...); }
-
-template <class _Fp, class _A0, class... _Args, class = __enable_if_bullet2<_Fp, _A0> >
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
-decltype((std::declval<_A0>().get().*std::declval<_Fp>())(std::declval<_Args>()...))
-__invoke(_Fp&& __f, _A0&& __a0, _Args&&... __args)
-    _NOEXCEPT_(noexcept((__a0.get().*__f)(static_cast<_Args&&>(__args)...)))
-               { return (__a0.get().*__f)(static_cast<_Args&&>(__args)...); }
-
-template <class _Fp, class _A0, class... _Args, class = __enable_if_bullet3<_Fp, _A0> >
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
-decltype(((*std::declval<_A0>()).*std::declval<_Fp>())(std::declval<_Args>()...))
-__invoke(_Fp&& __f, _A0&& __a0, _Args&&... __args)
-    _NOEXCEPT_(noexcept(((*static_cast<_A0&&>(__a0)).*__f)(static_cast<_Args&&>(__args)...)))
-               { return ((*static_cast<_A0&&>(__a0)).*__f)(static_cast<_Args&&>(__args)...); }
+template <>
+struct __invoker<1> {
+  template <class _Fp, class _A0, class... _Args>
+  static inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR auto _Fn(_Fp&& __f, _A0&& __a0, _Args&&... __args)
+      _LIBCPP_INLINE_EXPR((static_cast<_A0&&>(__a0).*__f)(static_cast<_Args&&>(__args)...));
+};
+
+template <>
+struct __invoker<2> {
+  template <class _Fp, class _A0, class... _Args>
+  static inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR auto _Fn(_Fp&& __f, _A0&& __a0, _Args&&... __args)
+      _LIBCPP_INLINE_EXPR((__a0.get().*__f)(static_cast<_Args&&>(__args)...));
+};
+
+template <>
+struct __invoker<3> {
+  template <class _Fp, class _A0, class... _Args>
+  static inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR auto _Fn(_Fp&& __f, _A0&& __a0, _Args&&... __args)
+      _LIBCPP_INLINE_EXPR(((*static_cast<_A0&&>(__a0)).*__f)(static_cast<_Args&&>(__args)...));
+};
 
 // bullets 4, 5 and 6
 
-template <class _Fp, class _A0, class = __enable_if_bullet4<_Fp, _A0> >
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
-decltype(std::declval<_A0>().*std::declval<_Fp>())
-__invoke(_Fp&& __f, _A0&& __a0)
-    _NOEXCEPT_(noexcept(static_cast<_A0&&>(__a0).*__f))
-               { return static_cast<_A0&&>(__a0).*__f; }
-
-template <class _Fp, class _A0, class = __enable_if_bullet5<_Fp, _A0> >
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
-decltype(std::declval<_A0>().get().*std::declval<_Fp>())
-__invoke(_Fp&& __f, _A0&& __a0)
-    _NOEXCEPT_(noexcept(__a0.get().*__f))
-               { return __a0.get().*__f; }
-
-template <class _Fp, class _A0, class = __enable_if_bullet6<_Fp, _A0> >
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
-decltype((*std::declval<_A0>()).*std::declval<_Fp>())
-__invoke(_Fp&& __f, _A0&& __a0)
-    _NOEXCEPT_(noexcept((*static_cast<_A0&&>(__a0)).*__f))
-               { return (*static_cast<_A0&&>(__a0)).*__f; }
-
-// bullet 7
+template <>
+struct __invoker<4> {
+  template <class _Fp, class _A0>
+  static inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR auto _Fn(_Fp&& __f, _A0&& __a0)
+      _LIBCPP_INLINE_EXPR(static_cast<_A0&&>(__a0).*__f);
+};
 
-template <class _Fp, class... _Args>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
-decltype(std::declval<_Fp>()(std::declval<_Args>()...))
-__invoke(_Fp&& __f, _Args&&... __args)
-    _NOEXCEPT_(noexcept(static_cast<_Fp&&>(__f)(static_cast<_Args&&>(__args)...)))
-               { return static_cast<_Fp&&>(__f)(static_cast<_Args&&>(__args)...); }
-// clang-format on
+template <>
+struct __invoker<5> {
+  template <class _Fp, class _A0>
+  static inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR auto _Fn(_Fp&& __f, _A0&& __a0)
+      _LIBCPP_INLINE_EXPR(__a0.get().*__f);
+};
 
-// __invokable
-template <class _Ret, class _Fp, class... _Args>
-struct __invokable_r {
-  template <class _XFp, class... _XArgs>
-  static decltype(std::__invoke(std::declval<_XFp>(), std::declval<_XArgs>()...)) __try_call(int);
-  template <class _XFp, class... _XArgs>
-  static __nat __try_call(...);
-
-  // FIXME: Check that _Ret, _Fp, and _Args... are all complete types, cv void,
-  // or incomplete array types as required by the standard.
-  using _Result _LIBCPP_NODEBUG = decltype(__try_call<_Fp, _Args...>(0));
-
-  using type              = __conditional_t<_IsNotSame<_Result, __nat>::value,
-                                            __conditional_t<is_void<_Ret>::value, true_type, __is_core_convertible<_Result, _Ret> >,
-                                            false_type>;
-  static const bool value = type::value;
+template <>
+struct __invoker<6> {
+  template <class _Fp, class _A0>
+  static inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR auto _Fn(_Fp&& __f, _A0&& __a0)
+      _LIBCPP_INLINE_EXPR((*static_cast<_A0&&>(__a0)).*__f);
 };
+
 template <class _Fp, class... _Args>
-using __is_invocable _LIBCPP_NODEBUG = __invokable_r<void, _Fp, _Args...>;
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR auto __invoke(_Fp&& __f, _Args&&... __args)
+    _LIBCPP_INLINE_EXPR(static_cast<_Fp&&>(__f)(static_cast<_Args&&>(__args)...));
 
-template <bool _IsInvokable, bool _IsCVVoid, class _Ret, class _Fp, class... _Args>
-struct __nothrow_invokable_r_imp {
-  static const bool value = false;
-};
+template <class _Fp, class _A0, class... _Args>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR auto __invoke(_Fp&& __f, _A0&& __a0, _Args&&... __args)
+    _LIBCPP_INLINE_EXPR(remove_reference<decltype(std::declval<typename std::__invoker_t<typename __member_pointer_traits<
+                                  __remove_cvref_t<_Fp>>::__self, _A0>>())>::type::
+        _Fn(static_cast<_Fp&&>(__f), static_cast<_A0&&>(__a0), static_cast<_Args&&>(__args)...));
 
-template <class _Ret, class _Fp, class... _Args>
-struct __nothrow_invokable_r_imp<true, false, _Ret, _Fp, _Args...> {
-  typedef __nothrow_invokable_r_imp _ThisT;
+#  undef _LIBCPP_INLINE_EXPR
 
-  template <class _Tp>
-  static void __test_noexcept(_Tp) _NOEXCEPT;
+// This is cheaper to compute than the non-SFINAE version, so prefer it when possible.
+template <class... _XArgs>
+using __sfinae_invoke_result_t _LIBCPP_NODEBUG = decltype(std::__invoke(std::declval<_XArgs>()...));
 
-#  ifdef _LIBCPP_CXX03_LANG
-  static const bool value = false;
-#  else
-  static const bool value =
-      noexcept(_ThisT::__test_noexcept<_Ret>(std::__invoke(std::declval<_Fp>(), std::declval<_Args>()...)));
-#  endif
+template <class... _Args>
+struct __invoke_result_impl<__void_t<__sfinae_invoke_result_t<_Args...> >, _Args...> {
+  using type _LIBCPP_NODEBUG = __sfinae_invoke_result_t<_Args...>;
 };
 
+// __invokable
+template <class, class _Ret, class _Fp, class... _Args>
+inline const bool __is_invocable_r_impl = false;
+
 template <class _Ret, class _Fp, class... _Args>
-struct __nothrow_invokable_r_imp<true, true, _Ret, _Fp, _Args...> {
-#  ifdef _LIBCPP_CXX03_LANG
-  static const bool value = false;
-#  else
-  static const bool value = noexcept(std::__invoke(std::declval<_Fp>(), std::declval<_Args>()...));
-#  endif
-};
+inline const bool __is_invocable_r_impl<decltype(void(std::__invoke(std::declval<_Fp>(), std::declval<_Args>()...))),
+                                        _Ret,
+                                        _Fp,
+                                        _Args...> =
+    is_void<_Ret>::value || __is_core_convertible<__sfinae_invoke_result_t<_Fp, _Args...>, _Ret>::value;
 
 template <class _Ret, class _Fp, class... _Args>
-using __nothrow_invokable_r _LIBCPP_NODEBUG =
-    __nothrow_invokable_r_imp<__invokable_r<_Ret, _Fp, _Args...>::value, is_void<_Ret>::value, _Ret, _Fp, _Args...>;
+inline const bool __is_invocable_r_v = __is_invocable_r_impl<void, _Ret, _Fp, _Args...>;
+
+template <class _Func, class... _Args>
+inline const bool __is_invocable_v = __is_invocable_r_v<void, _Func, _Args...>;
 
 template <class _Fp, class... _Args>
-using __nothrow_invokable _LIBCPP_NODEBUG =
-    __nothrow_invokable_r_imp<__is_invocable<_Fp, _Args...>::value, true, void, _Fp, _Args...>;
+using __is_invocable _LIBCPP_NODEBUG = _BoolConstant<__is_invocable_v<_Fp, _Args...> >;
 
-template <class _Func, class... _Args>
-inline const bool __is_invocable_v = __is_invocable<_Func, _Args...>::value;
+template <class, class _Func, class... _Args>
+inline const bool __is_nothrow_invocable_impl = false;
 
-template <class _Ret, class _Func, class... _Args>
-inline const bool __is_invocable_r_v = __invokable_r<_Ret, _Func, _Args...>::value;
+template <class _Func, class... _Args>
+inline const bool
+    __is_nothrow_invocable_impl<__enable_if_t<noexcept(std::__invoke(std::declval<_Func>(), std::declval<_Args>()...))>,
+                                _Func,
+                                _Args...> = true;
 
 template <class _Func, class... _Args>
-inline const bool __is_nothrow_invocable_v = __nothrow_invokable<_Func, _Args...>::value;
+inline const bool __is_nothrow_invocable_v = __is_nothrow_invocable_impl<void, _Func, _Args...>;
 
-template <class _Ret, class _Func, class... _Args>
-inline const bool __is_nothrow_invocable_r_v = __nothrow_invokable_r<_Ret, _Func, _Args...>::value;
+template <class, class _Ret, class _Fp, class... _Args>
+inline const bool __nothrow_invokable_r_imp = false;
 
-template <class _Func, class... _Args>
-struct __invoke_result
-    : enable_if<__is_invocable_v<_Func, _Args...>, typename __invokable_r<void, _Func, _Args...>::_Result> {};
+template <class _Ret, class _Fp, class... _Args>
+inline const bool __nothrow_invokable_r_imp<
+    __enable_if_t<noexcept(static_cast<void (*)(_Ret) noexcept>(nullptr)(
+        std::__invoke(std::declval<__enable_if_t<!is_void<_Ret>::value, _Fp>>(), std::declval<_Args>()...)))>,
+    _Ret,
+    _Fp,
+    _Args...> = true;
+
+template <class _Fp, class... _Args>
+inline const bool
+    __nothrow_invokable_r_imp<__enable_if_t<__is_nothrow_invocable_v<_Fp, _Args...>>, void, _Fp, _Args...> = true;
+
+template <class _Ret, class _Fp, class... _Args>
+inline const bool __is_nothrow_invocable_r_v _LIBCPP_NODEBUG =
+    __nothrow_invokable_r_imp<void, __conditional_t<is_void<_Ret>::value, void, _Ret>, _Fp, _Args...>;
+
+#endif // __has_builtin(__builtin_invoke)
 
 template <class _Func, class... _Args>
-using __invoke_result_t _LIBCPP_NODEBUG = typename __invoke_result<_Func, _Args...>::type;
+using __invoke_result _LIBCPP_NODEBUG = __invoke_result_impl<void, _Func, _Args...>;
 
-#endif // __has_builtin(__builtin_invoke_r)
+template <class _Func, class... _Args>
+using __invoke_result_t _LIBCPP_NODEBUG = typename __invoke_result_impl<void, _Func, _Args...>::type;
 
 template <class _Ret, class _Func, class... _Args>
 struct __is_invocable_r : integral_constant<bool, __is_invocable_r_v<_Ret, _Func, _Args...> > {};
 
-template <class _Ret, bool = is_void<_Ret>::value>
-struct __invoke_void_return_wrapper {
-  template <class... _Args>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static _Ret __call(_Args&&... __args) {
-    return std::__invoke(std::forward<_Args>(__args)...);
-  }
-};
-
-template <class _Ret>
-struct __invoke_void_return_wrapper<_Ret, true> {
-  template <class... _Args>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static void __call(_Args&&... __args) {
-    std::__invoke(std::forward<_Args>(__args)...);
-  }
-};
+template <class _Ret, class... _Args>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __enable_if_t<is_void<_Ret>::value, _Ret>
+__invoke_r(_Args&&... __args) _NOEXCEPT_(noexcept(std::__invoke(static_cast<_Args&&>(__args)...))) {
+  std::__invoke(static_cast<_Args&&>(__args)...);
+}
 
 template <class _Ret, class... _Args>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Ret __invoke_r(_Args&&... __args) {
-  return __invoke_void_return_wrapper<_Ret>::__call(std::forward<_Args>(__args)...);
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __enable_if_t<!is_void<_Ret>::value, _Ret>
+__invoke_r(_Args&&... __args) _NOEXCEPT_(noexcept(std::__invoke(static_cast<_Args&&>(__args)...))) {
+  return std::__invoke(static_cast<_Args&&>(__args)...);
 }
 
 #if _LIBCPP_STD_VER >= 17
@@ -389,7 +346,7 @@ _LIBCPP_NO_SPECIALIZATIONS inline constexpr bool is_nothrow_invocable_r_v =
     __is_nothrow_invocable_r_v<_Ret, _Fn, _Args...>;
 
 template <class _Fn, class... _Args>
-struct _LIBCPP_NO_SPECIALIZATIONS invoke_result : __invoke_result<_Fn, _Args...> {};
+struct _LIBCPP_NO_SPECIALIZATIONS invoke_result : __invoke_result_impl<void, _Fn, _Args...> {};
 
 template <class _Fn, class... _Args>
 using invoke_result_t = __invoke_result_t<_Fn, _Args...>;



More information about the libcxx-commits mailing list