1// add_rvalue_reference.hpp ---------------------------------------------------------//
2
3// Copyright 2010 Vicente J. Botet Escriba
4
5// Distributed under the Boost Software License, Version 1.0.
6// See http://www.boost.org/LICENSE_1_0.txt
7
8#ifndef BOOST_TYPE_TRAITS_EXT_ADD_RVALUE_REFERENCE__HPP
9#define BOOST_TYPE_TRAITS_EXT_ADD_RVALUE_REFERENCE__HPP
10
11#include <boost/config.hpp>
12
13//----------------------------------------------------------------------------//
14
15#include <boost/type_traits/is_void.hpp>
16#include <boost/type_traits/is_reference.hpp>
17
18//----------------------------------------------------------------------------//
19// //
20// C++03 implementation of //
21// 20.9.7.2 Reference modifications [meta.trans.ref] //
22// Written by Vicente J. Botet Escriba //
23// //
24// If T names an object or function type then the member typedef type
25// shall name T&&; otherwise, type shall name T. [ Note: This rule reflects
26// the semantics of reference collapsing. For example, when a type T names
27// a type T1&, the type add_rvalue_reference<T>::type is not an rvalue
28// reference. -end note ]
29//----------------------------------------------------------------------------//
30
31namespace boost {
32
33namespace type_traits_detail {
34
35 template <typename T, bool b>
36 struct add_rvalue_reference_helper
37 { typedef T type; };
38
39#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
40 template <typename T>
41 struct add_rvalue_reference_helper<T, true>
42 {
43 typedef T&& type;
44 };
45#endif
46
47 template <typename T>
48 struct add_rvalue_reference_imp
49 {
50 typedef typename boost::type_traits_detail::add_rvalue_reference_helper
51 <T, (is_void<T>::value == false && is_reference<T>::value == false) >::type type;
52 };
53
54}
55
56template <class T> struct add_rvalue_reference
57{
58 typedef typename boost::type_traits_detail::add_rvalue_reference_imp<T>::type type;
59};
60
61#if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES)
62
63 template <class T> using add_rvalue_reference_t = typename add_rvalue_reference<T>::type;
64
65#endif
66
67} // namespace boost
68
69#endif // BOOST_TYPE_TRAITS_EXT_ADD_RVALUE_REFERENCE__HPP
70
71