| // |
| // traits/static_require.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_REQUIRE_HPP |
| #define BOOST_ASIO_TRAITS_STATIC_REQUIRE_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/traits/static_query.hpp> |
| |
| #if defined(BOOST_ASIO_HAS_DECLTYPE) \ |
| && defined(BOOST_ASIO_HAS_NOEXCEPT) |
| # define BOOST_ASIO_HAS_DEDUCED_STATIC_REQUIRE_TRAIT 1 |
| #endif // defined(BOOST_ASIO_HAS_DECLTYPE) |
| // && defined(BOOST_ASIO_HAS_NOEXCEPT) |
| |
| #include <boost/asio/detail/push_options.hpp> |
| |
| namespace boost { |
| namespace asio { |
| namespace traits { |
| |
| template <typename T, typename Property, typename = void> |
| struct static_require_default; |
| |
| template <typename T, typename Property, typename = void> |
| struct static_require; |
| |
| } // namespace traits |
| namespace detail { |
| |
| struct no_static_require |
| { |
| BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = false); |
| }; |
| |
| template <typename T, typename Property, typename = void> |
| struct static_require_trait : |
| conditional< |
| is_same<T, typename decay<T>::type>::value |
| && is_same<Property, typename decay<Property>::type>::value, |
| no_static_require, |
| traits::static_require< |
| typename decay<T>::type, |
| typename decay<Property>::type> |
| >::type |
| { |
| }; |
| |
| #if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_REQUIRE_TRAIT) |
| |
| #if defined(BOOST_ASIO_HAS_WORKING_EXPRESSION_SFINAE) |
| |
| template <typename T, typename Property> |
| struct static_require_trait<T, Property, |
| typename enable_if< |
| decay<Property>::type::value() == traits::static_query<T, Property>::value() |
| >::type> |
| { |
| BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true); |
| }; |
| |
| #else // defined(BOOST_ASIO_HAS_WORKING_EXPRESSION_SFINAE) |
| |
| false_type static_require_test(...); |
| |
| template <typename T, typename Property> |
| true_type static_require_test(T*, Property*, |
| typename enable_if< |
| Property::value() == traits::static_query<T, Property>::value() |
| >::type* = 0); |
| |
| template <typename T, typename Property> |
| struct has_static_require |
| { |
| BOOST_ASIO_STATIC_CONSTEXPR(bool, value = |
| decltype((static_require_test)( |
| static_cast<T*>(0), static_cast<Property*>(0)))::value); |
| }; |
| |
| template <typename T, typename Property> |
| struct static_require_trait<T, Property, |
| typename enable_if< |
| has_static_require<typename decay<T>::type, |
| typename decay<Property>::type>::value |
| >::type> |
| { |
| BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true); |
| }; |
| |
| #endif // defined(BOOST_ASIO_HAS_WORKING_EXPRESSION_SFINAE) |
| |
| #endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_REQUIRE_TRAIT) |
| |
| } // namespace detail |
| namespace traits { |
| |
| template <typename T, typename Property, typename> |
| struct static_require_default : detail::static_require_trait<T, Property> |
| { |
| }; |
| |
| template <typename T, typename Property, typename> |
| struct static_require : static_require_default<T, Property> |
| { |
| }; |
| |
| } // namespace traits |
| } // namespace asio |
| } // namespace boost |
| |
| #include <boost/asio/detail/pop_options.hpp> |
| |
| #endif // BOOST_ASIO_TRAITS_STATIC_REQUIRE_HPP |