Relax overload resolution of any_receiver's completion functions

maikel · maikel · commit 78963fec0683 · 2024-12-18T20:56:55.000+01:00
diff --git a/include/exec/any_sender_of.hpp b/include/exec/any_sender_of.hpp
@@ -440,9 +440,7 @@ namespace exec {
         (*__other.__vtable_)(__copy_construct, this, __other);
       }
 
-      auto operator=(const __t& __other) -> __t&
-        requires(_Copyable)
-      {
+      auto operator=(const __t& __other) -> __t& requires(_Copyable) {
         if (&__other != this) {
           __t tmp(__other);
           *this = std::move(tmp);
@@ -520,7 +518,8 @@ namespace exec {
       }
 
       template <class _Tp>
-      STDEXEC_MEMFN_DECL(void __move_construct)(this __mtype<_Tp>, __t& __self, __t&& __other) noexcept {
+      STDEXEC_MEMFN_DECL(
+        void __move_construct)(this __mtype<_Tp>, __t& __self, __t&& __other) noexcept {
         if (!__other.__object_pointer_) {
           return;
         }
@@ -540,8 +539,7 @@ namespace exec {
 
       template <class _Tp>
         requires _Copyable
-      STDEXEC_MEMFN_DECL(
-        void __copy_construct)(this __mtype<_Tp>, __t& __self, const __t& __other) {
+      STDEXEC_MEMFN_DECL(void __copy_construct)(this __mtype<_Tp>, __t& __self, const __t& __other) {
         if (!__other.__object_pointer_) {
           return;
         }
@@ -563,7 +561,8 @@ namespace exec {
 
     struct __empty_vtable {
       template <class _Sender>
-      STDEXEC_MEMFN_DECL(auto __create_vtable)(this __mtype<__empty_vtable>, __mtype<_Sender>) noexcept
+      STDEXEC_MEMFN_DECL(
+        auto __create_vtable)(this __mtype<__empty_vtable>, __mtype<_Sender>) noexcept
         -> const __empty_vtable* {
         static const __empty_vtable __vtable_{};
         return &__vtable_;
@@ -616,11 +615,12 @@ namespace exec {
           , public __query_vfun<_Queries>... {
          public:
           using __query_vfun<_Queries>::operator()...;
+          using __any_::__rcvr_vfun<_Sigs>::operator()...;
 
          private:
           template <class _Rcvr>
             requires receiver_of<_Rcvr, completion_signatures<_Sigs...>>
-                    && (__callable<__query_vfun_fn<_Rcvr>, _Queries> && ...)
+                  && (__callable<__query_vfun_fn<_Rcvr>, _Queries> && ...)
           STDEXEC_MEMFN_DECL(
             auto __create_vtable)(this __mtype<__t>, __mtype<_Rcvr>) noexcept -> const __t* {
             static const __t __vtable_{
@@ -675,33 +675,30 @@ namespace exec {
         }
 
         template <class... _As>
-          requires __one_of<set_value_t(_As...), _Sigs...>
+          requires __callable<__vtable_t, void*, set_value_t, _As...>
         void set_value(_As&&... __as) noexcept {
-          const __any_::__rcvr_vfun<set_value_t(_As...)>* __vfun = __env_.__vtable_;
-          (*__vfun->__complete_)(__env_.__rcvr_, static_cast<_As&&>(__as)...);
+          (*__env_.__vtable_)(__env_.__rcvr_, set_value_t(), static_cast<_As&&>(__as)...);
         }
 
         template <class _Error>
-          requires __one_of<set_error_t(_Error), _Sigs...>
+          requires __callable<__vtable_t, void*, set_error_t, _Error>
         void set_error(_Error&& __err) noexcept {
-          const __any_::__rcvr_vfun<set_error_t(_Error)>* __vfun = __env_.__vtable_;
-          (*__vfun->__complete_)(__env_.__rcvr_, static_cast<_Error&&>(__err));
+          (*__env_.__vtable_)(__env_.__rcvr_, set_error_t(), static_cast<_Error&&>(__err));
         }
 
         void set_stopped() noexcept
-          requires __one_of<set_stopped_t(), _Sigs...>
+          requires __callable<__vtable_t, void*, set_stopped_t>
         {
-          const __any_::__rcvr_vfun<set_stopped_t()>* __vfun = __env_.__vtable_;
-          (*__vfun->__complete_)(__env_.__rcvr_);
+          (*__env_.__vtable_)(__env_.__rcvr_, set_stopped_t());
         }
 
         auto get_env() const noexcept -> const __env_t& {
           return __env_;
         }
       };
 
-      auto __test_never_stop_token(
-        get_stop_token_t (*)(never_stop_token (*)() noexcept)) -> __mbool<true>;
+      auto __test_never_stop_token(get_stop_token_t (*)(never_stop_token (*)() noexcept))
+        -> __mbool<true>;
 
       template <class _Tag, class _Ret, class... _As>
       auto __test_never_stop_token(_Tag (*)(_Ret (*)(_As...) noexcept)) -> __mbool<false>;
@@ -783,7 +780,8 @@ namespace exec {
 
      private:
       template <class _Op>
-      STDEXEC_MEMFN_DECL(auto __create_vtable)(this __mtype<__operation_vtable>, __mtype<_Op>) noexcept
+      STDEXEC_MEMFN_DECL(
+        auto __create_vtable)(this __mtype<__operation_vtable>, __mtype<_Op>) noexcept
         -> const __operation_vtable* {
         static __operation_vtable __vtable{[](void* __object_pointer) noexcept -> void {
           STDEXEC_ASSERT(__object_pointer);
@@ -831,8 +829,7 @@ namespace exec {
 
         template <same_as<__t> _Self, class _Item>
           requires __callable<set_next_t, _Receiver&, _Item>
-        STDEXEC_MEMFN_DECL(
-          auto set_next)(this _Self& __self, _Item&& __item) noexcept
+        STDEXEC_MEMFN_DECL(auto set_next)(this _Self& __self, _Item&& __item) noexcept
           -> __call_result_t<set_next_t, _Receiver&, _Item> {
           return exec::set_next(__self.__op_->__rcvr_, static_cast<_Item&&>(__item));
         }
@@ -961,7 +958,9 @@ namespace exec {
         __immovable_operation_storage (*__connect_)(void*, __receiver_ref_t);
        private:
         template <sender_to<__receiver_ref_t> _Sender>
-        STDEXEC_MEMFN_DECL(auto __create_vtable)(this __mtype<__vtable>, __mtype<_Sender>) noexcept -> const __vtable* {
+        STDEXEC_MEMFN_DECL(
+          auto
+          __create_vtable)(this __mtype<__vtable>, __mtype<_Sender>) noexcept -> const __vtable* {
           static const __vtable __vtable_{
             {*__create_vtable(__mtype<__query_vtable<_SenderQueries>>{}, __mtype<_Sender>{})},
             [](void* __object_pointer, __receiver_ref_t __receiver)
@@ -1083,7 +1082,9 @@ namespace exec {
         }
        private:
         template <scheduler _Scheduler>
-        STDEXEC_MEMFN_DECL(auto __create_vtable)(this __mtype<__vtable>, __mtype<_Scheduler>) noexcept -> const __vtable* {
+        STDEXEC_MEMFN_DECL(
+          auto
+          __create_vtable)(this __mtype<__vtable>, __mtype<_Scheduler>) noexcept -> const __vtable* {
           static const __vtable __vtable_{
             {*__create_vtable(
               __mtype<__query_vtable<_SchedulerQueries, false>>{}, __mtype<_Scheduler>{})},
diff --git a/include/stdexec/__detail/__receiver_ref.hpp b/include/stdexec/__detail/__receiver_ref.hpp
@@ -30,16 +30,16 @@ namespace stdexec { namespace __any_ {
 
   template <class _Tag, class... _Args>
   struct __rcvr_vfun<_Tag(_Args...)> {
-    void (*__complete_)(void*, _Args&&...) noexcept;
+    void (*__complete_)(void*, _Args...) noexcept;
 
-    void operator()(void* __obj, _Tag, _Args&&... __args) const noexcept {
+    void operator()(void* __obj, _Tag, _Args... __args) const noexcept {
       __complete_(__obj, static_cast<_Args&&>(__args)...);
     }
   };
 
   template <class _GetReceiver = std::identity, class _Obj, class _Tag, class... _Args>
   constexpr auto __rcvr_vfun_fn(_Obj*, _Tag (*)(_Args...)) noexcept {
-    return +[](void* __ptr, _Args&&... __args) noexcept {
+    return +[](void* __ptr, _Args... __args) noexcept {
       _Obj* __obj = static_cast<_Obj*>(__ptr);
       _Tag()(std::move(_GetReceiver()(*__obj)), static_cast<_Args&&>(__args)...);
     };
@@ -95,16 +95,20 @@ namespace stdexec { namespace __any_ {
     }
 
     template <class... _As>
+      requires __callable<__receiver_vtable_for<_Sigs, _Env>, void*, set_value_t, _As...>
     void set_value(_As&&... __as) noexcept {
       (*__vtable_)(__op_state_, set_value_t(), static_cast<_As&&>(__as)...);
     }
 
     template <class _Error>
+      requires __callable<__receiver_vtable_for<_Sigs, _Env>, void*, set_error_t, _Error>
     void set_error(_Error&& __err) noexcept {
       (*__vtable_)(__op_state_, set_error_t(), static_cast<_Error&&>(__err));
     }
 
-    void set_stopped() noexcept {
+    void set_stopped() noexcept
+      requires __callable<__receiver_vtable_for<_Sigs, _Env>, void*, set_stopped_t>
+    {
       (*__vtable_)(__op_state_, set_stopped_t());
     }
 
diff --git a/test/exec/test_any_sender.cpp b/test/exec/test_any_sender.cpp
@@ -36,8 +36,8 @@ namespace {
     template <class T>
     // BUGBUG ambiguous!
       requires stdexec::tag_invocable<tag_t, T>
-    auto operator()(T&& t) const
-      noexcept(stdexec::nothrow_tag_invocable<tag_t, T>) -> stdexec::tag_invoke_result_t<tag_t, T> {
+    auto operator()(T&& t) const noexcept(stdexec::nothrow_tag_invocable<tag_t, T>)
+      -> stdexec::tag_invoke_result_t<tag_t, T> {
       return stdexec::tag_invoke(*this, static_cast<T&&>(t));
     }
   };
@@ -328,6 +328,23 @@ namespace {
     }
   }
 
+  template <class... Vals>
+  using my_stoppable_sender_of =
+    any_sender_of<set_value_t(Vals)..., set_error_t(std::exception_ptr), set_stopped_t()>;
+
+  TEST_CASE("any_sender uses overload rules for completion signatures", "[types][any_sender]") {
+    auto split_sender = split(just(21));
+    static_assert(sender_of<decltype(split_sender), set_error_t(const std::exception_ptr&)>);
+    static_assert(sender_of<decltype(split_sender), set_value_t(const int&)>);
+    my_stoppable_sender_of<int> sender = split_sender;
+
+    auto [value] = *sync_wait(std::move(sender));
+    CHECK(value == 42);
+
+    sender = just(21) | then([&](int) -> int { throw 420; });
+    CHECK_THROWS_AS(sync_wait(std::move(sender)), int);
+  }
+
   class stopped_token {
    private:
     bool stopped_{true};
@@ -686,8 +703,8 @@ namespace {
         return {{}, static_cast<R&&>(r)};
       }
 
-      auto
-        query(ex::get_completion_scheduler_t<ex::set_value_t>) const noexcept -> counting_scheduler {
+      auto query(ex::get_completion_scheduler_t<ex::set_value_t>) const noexcept
+        -> counting_scheduler {
         return {};
       }
 
