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