ceph/src/boost/boost/type_traits/add_rvalue_reference.hpp

   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
  31 namespace boost {
  32
  33 namespace 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
  56 template <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