mirror of
https://github.com/30hours/blah2.git
synced 2024-11-08 12:25:42 +00:00
142 lines
3.3 KiB
C++
142 lines
3.3 KiB
C++
//
|
|
// awaitable.hpp
|
|
// ~~~~~~~~~~~~~
|
|
//
|
|
// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
|
|
//
|
|
// Distributed under the Boost Software License, Version 1.0. (See accompanying
|
|
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
|
//
|
|
|
|
#ifndef ASIO_AWAITABLE_HPP
|
|
#define ASIO_AWAITABLE_HPP
|
|
|
|
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
|
|
# pragma once
|
|
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
|
|
|
|
#include "asio/detail/config.hpp"
|
|
|
|
#if defined(ASIO_HAS_CO_AWAIT) || defined(GENERATING_DOCUMENTATION)
|
|
|
|
#if defined(ASIO_HAS_STD_COROUTINE)
|
|
# include <coroutine>
|
|
#else // defined(ASIO_HAS_STD_COROUTINE)
|
|
# include <experimental/coroutine>
|
|
#endif // defined(ASIO_HAS_STD_COROUTINE)
|
|
|
|
#include <utility>
|
|
#include "asio/any_io_executor.hpp"
|
|
|
|
#include "asio/detail/push_options.hpp"
|
|
|
|
namespace asio {
|
|
namespace detail {
|
|
|
|
#if defined(ASIO_HAS_STD_COROUTINE)
|
|
using std::coroutine_handle;
|
|
using std::suspend_always;
|
|
#else // defined(ASIO_HAS_STD_COROUTINE)
|
|
using std::experimental::coroutine_handle;
|
|
using std::experimental::suspend_always;
|
|
#endif // defined(ASIO_HAS_STD_COROUTINE)
|
|
|
|
template <typename> class awaitable_thread;
|
|
template <typename, typename> class awaitable_frame;
|
|
|
|
} // namespace detail
|
|
|
|
/// The return type of a coroutine or asynchronous operation.
|
|
template <typename T, typename Executor = any_io_executor>
|
|
class ASIO_NODISCARD awaitable
|
|
{
|
|
public:
|
|
/// The type of the awaited value.
|
|
typedef T value_type;
|
|
|
|
/// The executor type that will be used for the coroutine.
|
|
typedef Executor executor_type;
|
|
|
|
/// Default constructor.
|
|
constexpr awaitable() noexcept
|
|
: frame_(nullptr)
|
|
{
|
|
}
|
|
|
|
/// Move constructor.
|
|
awaitable(awaitable&& other) noexcept
|
|
: frame_(std::exchange(other.frame_, nullptr))
|
|
{
|
|
}
|
|
|
|
/// Destructor
|
|
~awaitable()
|
|
{
|
|
if (frame_)
|
|
frame_->destroy();
|
|
}
|
|
|
|
/// Move assignment.
|
|
awaitable& operator=(awaitable&& other) noexcept
|
|
{
|
|
if (this != &other)
|
|
frame_ = std::exchange(other.frame_, nullptr);
|
|
return *this;
|
|
}
|
|
|
|
/// Checks if the awaitable refers to a future result.
|
|
bool valid() const noexcept
|
|
{
|
|
return !!frame_;
|
|
}
|
|
|
|
#if !defined(GENERATING_DOCUMENTATION)
|
|
|
|
// Support for co_await keyword.
|
|
bool await_ready() const noexcept
|
|
{
|
|
return false;
|
|
}
|
|
|
|
// Support for co_await keyword.
|
|
template <class U>
|
|
void await_suspend(
|
|
detail::coroutine_handle<detail::awaitable_frame<U, Executor>> h)
|
|
{
|
|
frame_->push_frame(&h.promise());
|
|
}
|
|
|
|
// Support for co_await keyword.
|
|
T await_resume()
|
|
{
|
|
return awaitable(static_cast<awaitable&&>(*this)).frame_->get();
|
|
}
|
|
|
|
#endif // !defined(GENERATING_DOCUMENTATION)
|
|
|
|
private:
|
|
template <typename> friend class detail::awaitable_thread;
|
|
template <typename, typename> friend class detail::awaitable_frame;
|
|
|
|
// Not copy constructible or copy assignable.
|
|
awaitable(const awaitable&) = delete;
|
|
awaitable& operator=(const awaitable&) = delete;
|
|
|
|
// Construct the awaitable from a coroutine's frame object.
|
|
explicit awaitable(detail::awaitable_frame<T, Executor>* a)
|
|
: frame_(a)
|
|
{
|
|
}
|
|
|
|
detail::awaitable_frame<T, Executor>* frame_;
|
|
};
|
|
|
|
} // namespace asio
|
|
|
|
#include "asio/detail/pop_options.hpp"
|
|
|
|
#include "asio/impl/awaitable.hpp"
|
|
|
|
#endif // defined(ASIO_HAS_CO_AWAIT) || defined(GENERATING_DOCUMENTATION)
|
|
|
|
#endif // ASIO_AWAITABLE_HPP
|