Edit: /usr/include/boost/asio/awaitable.hpp (3270B)
//
// awaitable.hpp
// ~~~~~~~~~~~~~
//
// Copyright (c) 2003-2020 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 BOOST_ASIO_AWAITABLE_HPP
#define BOOST_ASIO_AWAITABLE_HPP
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
#include
#if defined(BOOST_ASIO_HAS_CO_AWAIT) || defined(GENERATING_DOCUMENTATION)
#if defined(BOOST_ASIO_HAS_STD_COROUTINE)
# include
#else // defined(BOOST_ASIO_HAS_STD_COROUTINE)
# include
#endif // defined(BOOST_ASIO_HAS_STD_COROUTINE)
#include
#include
namespace boost {
namespace asio {
namespace detail {
#if defined(BOOST_ASIO_HAS_STD_COROUTINE)
using std::coroutine_handle;
using std::suspend_always;
#else // defined(BOOST_ASIO_HAS_STD_COROUTINE)
using std::experimental::coroutine_handle;
using std::experimental::suspend_always;
#endif // defined(BOOST_ASIO_HAS_STD_COROUTINE)
template class awaitable_thread;
template class awaitable_frame;
} // namespace detail
/// The return type of a coroutine or asynchronous operation.
template
class 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();
}
/// 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
void await_suspend(
detail::coroutine_handle> h)
{
frame_->push_frame(&h.promise());
}
// Support for co_await keyword.
T await_resume()
{
return awaitable(static_cast(*this)).frame_->get();
}
#endif // !defined(GENERATING_DOCUMENTATION)
private:
template friend class detail::awaitable_thread;
template 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* a)
: frame_(a)
{
}
detail::awaitable_frame* frame_;
};
} // namespace asio
} // namespace boost
#include
#include
#endif // defined(BOOST_ASIO_HAS_CO_AWAIT) || defined(GENERATING_DOCUMENTATION)
#endif // BOOST_ASIO_AWAITABLE_HPP