1 // 2 // detail/non_const_lvalue.hpp 3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~ 4 // 5 // Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com) 6 // 7 // Distributed under the Boost Software License, Version 1.0. (See accompanying 8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 9 // 10 11 #ifndef BOOST_ASIO_DETAIL_NON_CONST_LVALUE_HPP 12 #define BOOST_ASIO_DETAIL_NON_CONST_LVALUE_HPP 13 14 #if defined(_MSC_VER) && (_MSC_VER >= 1200) 15 # pragma once 16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) 17 18 #include <boost/asio/detail/config.hpp> 19 #include <boost/asio/detail/type_traits.hpp> 20 21 #include <boost/asio/detail/push_options.hpp> 22 23 namespace boost { 24 namespace asio { 25 namespace detail { 26 27 template <typename T> 28 struct non_const_lvalue 29 { 30 #if defined(BOOST_ASIO_HAS_MOVE) non_const_lvalueboost::asio::detail::non_const_lvalue31 explicit non_const_lvalue(T& t) 32 : value(static_cast<typename conditional< 33 is_same<T, typename decay<T>::type>::value, 34 typename decay<T>::type&, T&&>::type>(t)) 35 { 36 } 37 38 typename conditional<is_same<T, typename decay<T>::type>::value, 39 typename decay<T>::type&, typename decay<T>::type>::type value; 40 #else // defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION) 41 explicit non_const_lvalue(const typename decay<T>::type& t) 42 : value(t) 43 { 44 } 45 46 typename decay<T>::type value; 47 #endif // defined(BOOST_ASIO_HAS_MOVE) 48 }; 49 50 } // namespace detail 51 } // namespace asio 52 } // namespace boost 53 54 #include <boost/asio/detail/pop_options.hpp> 55 56 #endif // BOOST_ASIO_DETAIL_NON_CONST_LVALUE_HPP 57