ceph/src/boost/libs/detail/include/boost/detail/reference_content.hpp

   1 //-----------------------------------------------------------------------------
   2 // boost detail/reference_content.hpp header file
   3 // See http://www.boost.org for updates, documentation, and revision history.
   4 //-----------------------------------------------------------------------------
   5 //
   6 // Copyright (c) 2003
   7 // Eric Friedman
   8 //
   9 // Distributed under the Boost Software License, Version 1.0. (See
  10 // accompanying file LICENSE_1_0.txt or copy at
  11 // http://www.boost.org/LICENSE_1_0.txt)
  12
  13 #ifndef BOOST_DETAIL_REFERENCE_CONTENT_HPP
  14 #define BOOST_DETAIL_REFERENCE_CONTENT_HPP
  15
  16 #include "boost/config.hpp"
  17
  18 #   include "boost/mpl/bool.hpp"
  19 #   include "boost/type_traits/has_nothrow_copy.hpp"
  20
  21 #include "boost/mpl/void.hpp"
  22
  23 namespace boost {
  24
  25 namespace detail {
  26
  27 ///////////////////////////////////////////////////////////////////////////////
  28 // (detail) class template reference_content
  29 //
  30 // Non-Assignable wrapper for references.
  31 //
  32 template <typename RefT>
  33 class reference_content
  34 {
  35 private: // representation
  36
  37     RefT content_;
  38
  39 public: // structors
  40
  41     ~reference_content()
  42     {
  43     }
  44
  45     reference_content(RefT r)
  46         : content_( r )
  47     {
  48     }
  49
  50     reference_content(const reference_content& operand)
  51         : content_( operand.content_ )
  52     {
  53     }
  54
  55 private: // non-Assignable
  56
  57     reference_content& operator=(const reference_content&);
  58
  59 public: // queries
  60
  61     RefT get() const
  62     {
  63         return content_;
  64     }
  65
  66 };
  67
  68 ///////////////////////////////////////////////////////////////////////////////
  69 // (detail) metafunction make_reference_content
  70 //
  71 // Wraps with reference_content if specified type is reference.
  72 //
  73
  74 template <typename T = mpl::void_> struct make_reference_content;
  75
  76
  77 template <typename T>
  78 struct make_reference_content
  79 {
  80     typedef T type;
  81 };
  82
  83 template <typename T>
  84 struct make_reference_content< T& >
  85 {
  86     typedef reference_content<T&> type;
  87 };
  88
  89
  90 template <>
  91 struct make_reference_content< mpl::void_ >
  92 {
  93     template <typename T>
  94     struct apply
  95         : make_reference_content<T>
  96     {
  97     };
  98
  99     typedef mpl::void_ type;
 100 };
 101
 102 } // namespace detail
 103
 104 ///////////////////////////////////////////////////////////////////////////////
 105 // reference_content<T&> type traits specializations
 106 //
 107
 108
 109 template <typename T>
 110 struct has_nothrow_copy<
 111       ::boost::detail::reference_content< T& >
 112     >
 113     : mpl::true_
 114 {
 115 };
 116
 117
 118 } // namespace boost
 119
 120 #endif // BOOST_DETAIL_REFERENCE_CONTENT_HPP