blah2/lib/asio-1.26.0/asio/this_coro.hpp

281 lines
7.4 KiB
C++
Raw Normal View History

2023-05-04 11:25:37 +00:00
//
// this_coro.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_THIS_CORO_HPP
#define ASIO_THIS_CORO_HPP
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
#include "asio/detail/config.hpp"
#include "asio/detail/type_traits.hpp"
#include "asio/detail/push_options.hpp"
namespace asio {
namespace this_coro {
/// Awaitable type that returns the executor of the current coroutine.
struct executor_t
{
ASIO_CONSTEXPR executor_t()
{
}
};
/// Awaitable object that returns the executor of the current coroutine.
#if defined(ASIO_HAS_CONSTEXPR) || defined(GENERATING_DOCUMENTATION)
constexpr executor_t executor;
#elif defined(ASIO_MSVC)
__declspec(selectany) executor_t executor;
#endif
/// Awaitable type that returns the cancellation state of the current coroutine.
struct cancellation_state_t
{
ASIO_CONSTEXPR cancellation_state_t()
{
}
};
/// Awaitable object that returns the cancellation state of the current
/// coroutine.
/**
* @par Example
* @code asio::awaitable<void> my_coroutine()
* {
* asio::cancellation_state cs
* = co_await asio::this_coro::cancellation_state;
*
* // ...
*
* if (cs.cancelled() != asio::cancellation_type::none)
* // ...
* } @endcode
*/
#if defined(ASIO_HAS_CONSTEXPR) || defined(GENERATING_DOCUMENTATION)
constexpr cancellation_state_t cancellation_state;
#elif defined(ASIO_MSVC)
__declspec(selectany) cancellation_state_t cancellation_state;
#endif
#if defined(GENERATING_DOCUMENTATION)
/// Returns an awaitable object that may be used to reset the cancellation state
/// of the current coroutine.
/**
* Let <tt>P</tt> be the cancellation slot associated with the current
* coroutine's @ref co_spawn completion handler. Assigns a new
* asio::cancellation_state object <tt>S</tt>, constructed as
* <tt>S(P)</tt>, into the current coroutine's cancellation state object.
*
* @par Example
* @code asio::awaitable<void> my_coroutine()
* {
* co_await asio::this_coro::reset_cancellation_state();
*
* // ...
* } @endcode
*
* @note The cancellation state is shared by all coroutines in the same "thread
* of execution" that was created using asio::co_spawn.
*/
ASIO_NODISCARD ASIO_CONSTEXPR unspecified
reset_cancellation_state();
/// Returns an awaitable object that may be used to reset the cancellation state
/// of the current coroutine.
/**
* Let <tt>P</tt> be the cancellation slot associated with the current
* coroutine's @ref co_spawn completion handler. Assigns a new
* asio::cancellation_state object <tt>S</tt>, constructed as <tt>S(P,
* std::forward<Filter>(filter))</tt>, into the current coroutine's
* cancellation state object.
*
* @par Example
* @code asio::awaitable<void> my_coroutine()
* {
* co_await asio::this_coro::reset_cancellation_state(
* asio::enable_partial_cancellation());
*
* // ...
* } @endcode
*
* @note The cancellation state is shared by all coroutines in the same "thread
* of execution" that was created using asio::co_spawn.
*/
template <typename Filter>
ASIO_NODISCARD ASIO_CONSTEXPR unspecified
reset_cancellation_state(ASIO_MOVE_ARG(Filter) filter);
/// Returns an awaitable object that may be used to reset the cancellation state
/// of the current coroutine.
/**
* Let <tt>P</tt> be the cancellation slot associated with the current
* coroutine's @ref co_spawn completion handler. Assigns a new
* asio::cancellation_state object <tt>S</tt>, constructed as <tt>S(P,
* std::forward<InFilter>(in_filter),
* std::forward<OutFilter>(out_filter))</tt>, into the current coroutine's
* cancellation state object.
*
* @par Example
* @code asio::awaitable<void> my_coroutine()
* {
* co_await asio::this_coro::reset_cancellation_state(
* asio::enable_partial_cancellation(),
* asio::disable_cancellation());
*
* // ...
* } @endcode
*
* @note The cancellation state is shared by all coroutines in the same "thread
* of execution" that was created using asio::co_spawn.
*/
template <typename InFilter, typename OutFilter>
ASIO_NODISCARD ASIO_CONSTEXPR unspecified
reset_cancellation_state(
ASIO_MOVE_ARG(InFilter) in_filter,
ASIO_MOVE_ARG(OutFilter) out_filter);
/// Returns an awaitable object that may be used to determine whether the
/// coroutine throws if trying to suspend when it has been cancelled.
/**
* @par Example
* @code asio::awaitable<void> my_coroutine()
* {
* if (co_await asio::this_coro::throw_if_cancelled)
* // ...
*
* // ...
* } @endcode
*/
ASIO_NODISCARD ASIO_CONSTEXPR unspecified
throw_if_cancelled();
/// Returns an awaitable object that may be used to specify whether the
/// coroutine throws if trying to suspend when it has been cancelled.
/**
* @par Example
* @code asio::awaitable<void> my_coroutine()
* {
* co_await asio::this_coro::throw_if_cancelled(false);
*
* // ...
* } @endcode
*/
ASIO_NODISCARD ASIO_CONSTEXPR unspecified
throw_if_cancelled(bool value);
#else // defined(GENERATING_DOCUMENTATION)
struct reset_cancellation_state_0_t
{
ASIO_CONSTEXPR reset_cancellation_state_0_t()
{
}
};
ASIO_NODISCARD inline ASIO_CONSTEXPR reset_cancellation_state_0_t
reset_cancellation_state()
{
return reset_cancellation_state_0_t();
}
template <typename Filter>
struct reset_cancellation_state_1_t
{
template <typename F>
ASIO_CONSTEXPR reset_cancellation_state_1_t(
ASIO_MOVE_ARG(F) filt)
: filter(ASIO_MOVE_CAST(F)(filt))
{
}
Filter filter;
};
template <typename Filter>
ASIO_NODISCARD inline ASIO_CONSTEXPR reset_cancellation_state_1_t<
typename decay<Filter>::type>
reset_cancellation_state(ASIO_MOVE_ARG(Filter) filter)
{
return reset_cancellation_state_1_t<typename decay<Filter>::type>(
ASIO_MOVE_CAST(Filter)(filter));
}
template <typename InFilter, typename OutFilter>
struct reset_cancellation_state_2_t
{
template <typename F1, typename F2>
ASIO_CONSTEXPR reset_cancellation_state_2_t(
ASIO_MOVE_ARG(F1) in_filt, ASIO_MOVE_ARG(F2) out_filt)
: in_filter(ASIO_MOVE_CAST(F1)(in_filt)),
out_filter(ASIO_MOVE_CAST(F2)(out_filt))
{
}
InFilter in_filter;
OutFilter out_filter;
};
template <typename InFilter, typename OutFilter>
ASIO_NODISCARD inline ASIO_CONSTEXPR reset_cancellation_state_2_t<
typename decay<InFilter>::type,
typename decay<OutFilter>::type>
reset_cancellation_state(
ASIO_MOVE_ARG(InFilter) in_filter,
ASIO_MOVE_ARG(OutFilter) out_filter)
{
return reset_cancellation_state_2_t<
typename decay<InFilter>::type,
typename decay<OutFilter>::type>(
ASIO_MOVE_CAST(InFilter)(in_filter),
ASIO_MOVE_CAST(OutFilter)(out_filter));
}
struct throw_if_cancelled_0_t
{
ASIO_CONSTEXPR throw_if_cancelled_0_t()
{
}
};
ASIO_NODISCARD inline ASIO_CONSTEXPR throw_if_cancelled_0_t
throw_if_cancelled()
{
return throw_if_cancelled_0_t();
}
struct throw_if_cancelled_1_t
{
ASIO_CONSTEXPR throw_if_cancelled_1_t(bool val)
: value(val)
{
}
bool value;
};
ASIO_NODISCARD inline ASIO_CONSTEXPR throw_if_cancelled_1_t
throw_if_cancelled(bool value)
{
return throw_if_cancelled_1_t(value);
}
#endif // defined(GENERATING_DOCUMENTATION)
} // namespace this_coro
} // namespace asio
#include "asio/detail/pop_options.hpp"
#endif // ASIO_THIS_CORO_HPP