operation_state.hpp
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//
// execution/operation_state.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 ASIO_EXECUTION_OPERATION_STATE_HPP
#define ASIO_EXECUTION_OPERATION_STATE_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/execution/start.hpp"
#if defined(ASIO_HAS_DEDUCED_START_FREE_TRAIT) \
&& defined(ASIO_HAS_DEDUCED_START_MEMBER_TRAIT)
# define ASIO_HAS_DEDUCED_EXECUTION_IS_OPERATION_STATE_TRAIT 1
#endif // defined(ASIO_HAS_DEDUCED_START_FREE_TRAIT)
// && defined(ASIO_HAS_DEDUCED_START_MEMBER_TRAIT)
#include "asio/detail/push_options.hpp"
namespace asio {
namespace execution {
namespace detail {
template <typename T>
struct is_operation_state_base :
integral_constant<bool,
is_destructible<T>::value
&& is_object<T>::value
>
{
};
} // namespace detail
/// The is_operation_state trait detects whether a type T satisfies the
/// execution::operation_state concept.
/**
* Class template @c is_operation_state is a type trait that is derived from
* @c true_type if the type @c T meets the concept definition for an
* @c operation_state, otherwise @c false_type.
*/
template <typename T>
struct is_operation_state :
#if defined(GENERATING_DOCUMENTATION)
integral_constant<bool, automatically_determined>
#else // defined(GENERATING_DOCUMENTATION)
conditional<
can_start<typename add_lvalue_reference<T>::type>::value
&& is_nothrow_start<typename add_lvalue_reference<T>::type>::value,
detail::is_operation_state_base<T>,
false_type
>::type
#endif // defined(GENERATING_DOCUMENTATION)
{
};
#if defined(ASIO_HAS_VARIABLE_TEMPLATES)
template <typename T>
ASIO_CONSTEXPR const bool is_operation_state_v =
is_operation_state<T>::value;
#endif // defined(ASIO_HAS_VARIABLE_TEMPLATES)
#if defined(ASIO_HAS_CONCEPTS)
template <typename T>
ASIO_CONCEPT operation_state = is_operation_state<T>::value;
#define ASIO_EXECUTION_OPERATION_STATE \
::asio::execution::operation_state
#else // defined(ASIO_HAS_CONCEPTS)
#define ASIO_EXECUTION_OPERATION_STATE typename
#endif // defined(ASIO_HAS_CONCEPTS)
} // namespace execution
} // namespace asio
#include "asio/detail/pop_options.hpp"
#endif // ASIO_EXECUTION_OPERATION_STATE_HPP