1 // add_rvalue_reference.hpp ---------------------------------------------------------//
3 // Copyright 2010 Vicente J. Botet Escriba
5 // Distributed under the Boost Software License, Version 1.0.
6 // See http://www.boost.org/LICENSE_1_0.txt
8 #ifndef BOOST_TYPE_TRAITS_EXT_ADD_RVALUE_REFERENCE__HPP
9 #define BOOST_TYPE_TRAITS_EXT_ADD_RVALUE_REFERENCE__HPP
11 #include <boost/config.hpp>
13 //----------------------------------------------------------------------------//
15 #include <boost/type_traits/is_void.hpp>
16 #include <boost/type_traits/is_reference.hpp>
18 //----------------------------------------------------------------------------//
20 // C++03 implementation of //
21 // 20.9.7.2 Reference modifications [meta.trans.ref] //
22 // Written by Vicente J. Botet Escriba //
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 //----------------------------------------------------------------------------//
33 namespace type_traits_detail {
35 template <typename T, bool b>
36 struct add_rvalue_reference_helper
39 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
41 struct add_rvalue_reference_helper<T, true>
48 struct add_rvalue_reference_imp
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;
56 template <class T> struct add_rvalue_reference
58 typedef typename boost::type_traits_detail::add_rvalue_reference_imp<T>::type type;
61 #if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES)
63 template <class T> using add_rvalue_reference_t = typename add_rvalue_reference<T>::type;
69 #endif // BOOST_TYPE_TRAITS_EXT_ADD_RVALUE_REFERENCE__HPP