| // |
| // execution/operation_state.hpp |
| // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2021 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_EXECUTION_OPERATION_STATE_HPP |
| #define BOOST_ASIO_EXECUTION_OPERATION_STATE_HPP |
| |
| #if defined(_MSC_VER) && (_MSC_VER >= 1200) |
| # pragma once |
| #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) |
| |
| #include <boost/asio/detail/config.hpp> |
| #include <boost/asio/detail/type_traits.hpp> |
| #include <boost/asio/execution/start.hpp> |
| |
| #if defined(BOOST_ASIO_HAS_DEDUCED_START_FREE_TRAIT) \ |
| && defined(BOOST_ASIO_HAS_DEDUCED_START_MEMBER_TRAIT) |
| # define BOOST_ASIO_HAS_DEDUCED_EXECUTION_IS_OPERATION_STATE_TRAIT 1 |
| #endif // defined(BOOST_ASIO_HAS_DEDUCED_START_FREE_TRAIT) |
| // && defined(BOOST_ASIO_HAS_DEDUCED_START_MEMBER_TRAIT) |
| |
| #include <boost/asio/detail/push_options.hpp> |
| |
| namespace boost { |
| 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(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) |
| |
| template <typename T> |
| BOOST_ASIO_CONSTEXPR const bool is_operation_state_v = |
| is_operation_state<T>::value; |
| |
| #endif // defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) |
| |
| #if defined(BOOST_ASIO_HAS_CONCEPTS) |
| |
| template <typename T> |
| BOOST_ASIO_CONCEPT operation_state = is_operation_state<T>::value; |
| |
| #define BOOST_ASIO_EXECUTION_OPERATION_STATE \ |
| ::boost::asio::execution::operation_state |
| |
| #else // defined(BOOST_ASIO_HAS_CONCEPTS) |
| |
| #define BOOST_ASIO_EXECUTION_OPERATION_STATE typename |
| |
| #endif // defined(BOOST_ASIO_HAS_CONCEPTS) |
| |
| } // namespace execution |
| } // namespace asio |
| } // namespace boost |
| |
| #include <boost/asio/detail/pop_options.hpp> |
| |
| #endif // BOOST_ASIO_EXECUTION_OPERATION_STATE_HPP |