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https://gitlab.com/niansa/libcrosscoro.git
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c548433dd9
See issue for more details, in general attempting to implement a coro::thread_pool exposed that the coro::sync_wait and coro::when_all only worked if the coroutines executed on that same thread. They should now possibly have the ability to execute on another thread, to be determined in a later issue. Fixes #7
57 lines
1.6 KiB
C++
57 lines
1.6 KiB
C++
#pragma once
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#include <concepts>
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#include <coroutine>
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#include <type_traits>
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namespace coro
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{
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/**
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* This concept declares a type that is required to meet the c++20 coroutine operator co_await()
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* retun type. It requires the following three member functions:
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* await_ready() -> bool
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* await_suspend(std::coroutine_handle<>) -> void|bool|std::coroutine_handle<>
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* await_resume() -> decltype(auto)
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* Where the return type on await_resume is the requested return of the awaitable.
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*/
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template<typename T>
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concept awaiter_type = requires(T t, std::coroutine_handle<> c)
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{
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{ t.await_ready() } -> std::same_as<bool>;
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std::same_as<decltype(t.await_suspend(c)), void> ||
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std::same_as<decltype(t.await_suspend(c)), bool> ||
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std::same_as<decltype(t.await_suspend(c)), std::coroutine_handle<>>;
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{ t.await_resume() };
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};
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/**
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* This concept declares a type that can be operator co_await()'ed and returns an awaiter_type.
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*/
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template<typename T>
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concept awaitable_type = requires(T t)
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{
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// operator co_await()
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{ t.operator co_await() } -> awaiter_type;
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};
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template<awaitable_type awaitable, typename = void>
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struct awaitable_traits
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{
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};
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template<typename T>
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static auto get_awaiter(T&& value)
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{
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return static_cast<T&&>(value).operator co_await();
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}
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template<awaitable_type awaitable>
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struct awaitable_traits<awaitable>
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{
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using awaiter_t = decltype(get_awaiter(std::declval<awaitable>()));
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using awaiter_return_t = decltype(std::declval<awaiter_t>().await_resume());
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// using awaiter_return_decay_t = std::decay_t<decltype(std::declval<awaiter_t>().await_resume())>;
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};
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} // namespace coro
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