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- //
- // traits/static_query.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_TRAITS_STATIC_QUERY_HPP
- #define BOOST_ASIO_TRAITS_STATIC_QUERY_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>
- #if defined(BOOST_ASIO_HAS_DECLTYPE) \
- && defined(BOOST_ASIO_HAS_NOEXCEPT) \
- && defined(BOOST_ASIO_HAS_CONSTEXPR) \
- && defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) \
- && defined(BOOST_ASIO_HAS_WORKING_EXPRESSION_SFINAE)
- # define BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT 1
- #endif // defined(BOOST_ASIO_HAS_DECLTYPE)
- // && defined(BOOST_ASIO_HAS_NOEXCEPT)
- // && defined(BOOST_ASIO_HAS_CONSTEXPR)
- // && defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
- // && defined(BOOST_ASIO_HAS_WORKING_EXPRESSION_SFINAE)
- #include <boost/asio/detail/push_options.hpp>
- namespace boost {
- namespace asio {
- namespace traits {
- template <typename T, typename Property, typename = void>
- struct static_query_default;
- template <typename T, typename Property, typename = void>
- struct static_query;
- } // namespace traits
- namespace detail {
- struct no_static_query
- {
- BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = false);
- BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = false);
- };
- template <typename T, typename Property, typename = void>
- struct static_query_trait :
- conditional<
- is_same<T, typename decay<T>::type>::value
- && is_same<Property, typename decay<Property>::type>::value,
- no_static_query,
- traits::static_query<
- typename decay<T>::type,
- typename decay<Property>::type>
- >::type
- {
- };
- #if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
- template <typename T, typename Property>
- struct static_query_trait<T, Property,
- typename void_type<
- decltype(decay<Property>::type::template static_query_v<T>)
- >::type>
- {
- BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
- using result_type = decltype(
- decay<Property>::type::template static_query_v<T>);
- BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept =
- noexcept(decay<Property>::type::template static_query_v<T>));
- static BOOST_ASIO_CONSTEXPR result_type value() noexcept(is_noexcept)
- {
- return decay<Property>::type::template static_query_v<T>;
- }
- };
- #endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
- } // namespace detail
- namespace traits {
- template <typename T, typename Property, typename>
- struct static_query_default : detail::static_query_trait<T, Property>
- {
- };
- template <typename T, typename Property, typename>
- struct static_query : static_query_default<T, Property>
- {
- };
- } // namespace traits
- } // namespace asio
- } // namespace boost
- #include <boost/asio/detail/pop_options.hpp>
- #endif // BOOST_ASIO_TRAITS_STATIC_QUERY_HPP
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