把 awaitable 和 awaiter 的概念进行分离。

avplayer · Oct 21, 2024 · 9075f6a · 9075f6a
1 parent 0dca587
commit 9075f6a
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Showing 2 changed files with 45 additions and 26 deletions.
diff --git a/include/ucoro/awaitable.hpp b/include/ucoro/awaitable.hpp
@@ -58,6 +58,9 @@ namespace ucoro
 	template<typename T>
 	struct awaitable;
 
+	template<typename T>
+	struct awaitable_awaiter;
+
 	template<typename T>
 	struct awaitable_promise;
 
@@ -344,7 +347,7 @@ namespace ucoro
 				// 调用 co_await local_storage_t<T>
 				return local_storage_awaiter<traits::local_storage_value_type<std::decay_t<A>>>{this};
 			}
-			else if constexpr (concepts::is_awaitable_v<A>)
+			else if constexpr ( concepts::is_awaitable_v<std::decay_t<A>> )
 			{
 				// 调用 co_await awaitable<T>; 或者其他有三件套的类型
 				static_assert(std::is_rvalue_reference_v<A&&>, "co_await must be used on rvalue");
@@ -358,7 +361,7 @@ namespace ucoro
 			}
 			else
 			{
-				static_assert(0, "co_await must been used on an awaitable");
+				static_assert(0, "co_await must be called on an awaitable type");
 			}
 		}
 
@@ -419,28 +422,6 @@ namespace ucoro
 		awaitable& operator=(const awaitable&) = delete;
 		awaitable& operator=(awaitable&) = delete;
 
-		constexpr bool await_ready() const noexcept
-		{
-			return false;
-		}
-
-		T await_resume()
-		{
-			return current_coro_handle_.promise().get_value();
-		}
-
-		template<typename PromiseType>
-		auto await_suspend(std::coroutine_handle<PromiseType> continuation)
-		{
-			if constexpr (concepts::awaitable_promise_type<PromiseType>)
-			{
-				current_coro_handle_.promise().local_ = continuation.promise().local_;
-			}
-
-			current_coro_handle_.promise().continuation_ = continuation;
-			return current_coro_handle_;
-		}
-
 		void set_local(std::any local)
 		{
 			assert("local has value" && !current_coro_handle_.promise().local_);
@@ -500,9 +481,47 @@ namespace ucoro
 			return launched_coro;
 		}
 
+		awaitable_awaiter<T> operator co_await ()
+		{
+			return  awaitable_awaiter<T>{this};
+		}
+
 		std::coroutine_handle<promise_type> current_coro_handle_;
 	};
 
+	//////////////////////////////////////////////////////////////////////////
+	// awaitable 的等待器
+	template<typename T>
+	struct awaitable_awaiter
+	{
+		awaitable<T>* this_;
+
+		constexpr bool await_ready() const noexcept
+		{
+			return false;
+		}
+
+		T await_resume()
+		{
+			return this_->current_coro_handle_.promise().get_value();
+		}
+
+		template<typename PromiseType>
+		auto await_suspend(std::coroutine_handle<PromiseType> continuation)
+		{
+			if constexpr (concepts::awaitable_promise_type<PromiseType>)
+			{
+				auto& calee_promise = this_->current_coro_handle_.promise();
+				auto& caller_promise = continuation.promise();
+				calee_promise.local_ = caller_promise.local_;
+			}
+
+			this_->current_coro_handle_.promise().continuation_ = continuation;
+			return this_->current_coro_handle_;
+		}
+
+	};
+
 	//////////////////////////////////////////////////////////////////////////
 
 	template<typename T>

diff --git a/tests/test3/test.cpp b/tests/test3/test.cpp
@@ -16,8 +16,8 @@ int main(int argc, char **argv)
 	static_assert(ucoro::concepts::is_awaiter_v<CallbackAwaiterType0>, "not a coroutine");
 	static_assert(ucoro::concepts::is_awaiter_v<CallbackAwaiterType1>, "not a coroutine");
 
-	static_assert(ucoro::concepts::is_awaiter_v<ucoro::awaitable<void>>, "not a coroutine");
-	static_assert(ucoro::concepts::is_awaiter_v<ucoro::awaitable<int>>, "not a coroutine");
+	static_assert(ucoro::concepts::is_awaiter_v<ucoro::awaitable_awaiter<void>>, "not a coroutine");
+	static_assert(ucoro::concepts::is_awaiter_v<ucoro::awaitable_awaiter<int>>, "not a coroutine");
 
 	static_assert(!ucoro::concepts::is_awaiter_v<int>, "not a coroutine");