2025-01-12 19:51:34 +08:00

119 lines
3.7 KiB
C++

/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* Licensed under the Apache License Version 2.0 with LLVM Exceptions
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* https://llvm.org/LICENSE.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <unifex/config.hpp>
#include <unifex/receiver_concepts.hpp>
#include <unifex/sender_concepts.hpp>
#include <unifex/blocking.hpp>
#include <unifex/std_concepts.hpp>
#include <exception>
#include <tuple>
#include <type_traits>
#include <utility>
#include <unifex/detail/prologue.hpp>
namespace unifex {
namespace _just {
template <typename Receiver, typename... Values>
struct _op {
struct type;
};
template <typename Receiver, typename... Values>
using operation = typename _op<remove_cvref_t<Receiver>, Values...>::type;
template <typename Receiver, typename... Values>
struct _op<Receiver, Values...>::type {
UNIFEX_NO_UNIQUE_ADDRESS std::tuple<Values...> values_;
UNIFEX_NO_UNIQUE_ADDRESS Receiver receiver_;
void start() & noexcept {
UNIFEX_TRY {
std::apply(
[&](Values&&... values) {
unifex::set_value((Receiver &&) receiver_, (Values &&) values...);
},
std::move(values_));
} UNIFEX_CATCH (...) {
unifex::set_error((Receiver &&) receiver_, std::current_exception());
}
}
};
template <typename... Values>
struct _sender {
class type;
};
template <typename... Values>
using sender = typename _sender<std::decay_t<Values>...>::type;
template <typename... Values>
class _sender<Values...>::type {
UNIFEX_NO_UNIQUE_ADDRESS std::tuple<Values...> values_;
public:
template <
template <typename...> class Variant,
template <typename...> class Tuple>
using value_types = Variant<Tuple<Values...>>;
template <template <typename...> class Variant>
using error_types = Variant<std::exception_ptr>;
static constexpr bool sends_done = false;
template(typename... Values2)
(requires (sizeof...(Values2) == sizeof...(Values)) AND
constructible_from<std::tuple<Values...>, Values2...>)
explicit type(std::in_place_t, Values2&&... values)
noexcept(std::is_nothrow_constructible_v<std::tuple<Values...>, Values2...>)
: values_((Values2 &&) values...) {}
template(typename This, typename Receiver)
(requires same_as<remove_cvref_t<This>, type> AND
receiver<Receiver> AND
constructible_from<std::tuple<Values...>, member_t<This, std::tuple<Values...>>>)
friend auto tag_invoke(tag_t<connect>, This&& that, Receiver&& r)
noexcept(std::is_nothrow_constructible_v<std::tuple<Values...>, member_t<This, std::tuple<Values...>>>)
-> operation<Receiver, Values...> {
return {static_cast<This&&>(that).values_, static_cast<Receiver&&>(r)};
}
friend constexpr blocking_kind tag_invoke(tag_t<blocking>, const type&) noexcept {
return blocking_kind::always_inline;
}
};
} // namespace _just
namespace _just_cpo {
inline const struct just_fn {
template <typename... Values>
constexpr auto operator()(Values&&... values) const
noexcept(std::is_nothrow_constructible_v<_just::sender<Values...>, std::in_place_t, Values...>)
-> _just::sender<Values...> {
return _just::sender<Values...>{std::in_place, (Values&&)values...};
}
} just{};
} // namespace _just_cpo
using _just_cpo::just;
} // namespace unifex
#include <unifex/detail/epilogue.hpp>