ceph/src/boost/boost/variant/detail/backup_holder.hpp

   1 //-----------------------------------------------------------------------------
   2 // boost variant/detail/backup_holder.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_VARIANT_DETAIL_BACKUP_HOLDER_HPP
  14 #define BOOST_VARIANT_DETAIL_BACKUP_HOLDER_HPP
  15
  16 #include <boost/config.hpp>
  17 #include <boost/assert.hpp>
  18
  19 namespace boost {
  20 namespace detail { namespace variant {
  21
  22 template <typename T>
  23 class backup_holder
  24 {
  25 private: // representation
  26
  27     T* backup_;
  28
  29 public: // structors
  30
  31     ~backup_holder() BOOST_NOEXCEPT
  32     {
  33         delete backup_;
  34     }
  35
  36     explicit backup_holder(T* backup) BOOST_NOEXCEPT
  37         : backup_(backup)
  38     {
  39     }
  40
  41     backup_holder(const backup_holder&);
  42
  43 public: // modifiers
  44
  45     backup_holder& operator=(const backup_holder& rhs)
  46     {
  47         *backup_ = rhs.get();
  48         return *this;
  49     }
  50
  51     backup_holder& operator=(const T& rhs)
  52     {
  53         *backup_ = rhs;
  54         return *this;
  55     }
  56
  57     void swap(backup_holder& rhs) BOOST_NOEXCEPT
  58     {
  59         T* tmp = rhs.backup_;
  60         rhs.backup_ = this->backup_;
  61         this->backup_ = tmp;
  62     }
  63
  64 public: // queries
  65
  66     T& get() BOOST_NOEXCEPT
  67     {
  68         return *backup_;
  69     }
  70
  71     const T& get() const BOOST_NOEXCEPT
  72     {
  73         return *backup_;
  74     }
  75
  76 };
  77
  78 template <typename T>
  79 backup_holder<T>::backup_holder(const backup_holder&)
  80     : backup_(0)
  81 {
  82     // not intended for copy, but do not want to prohibit syntactically
  83     BOOST_ASSERT(false);
  84 }
  85
  86 template <typename T>
  87 void swap(backup_holder<T>& lhs, backup_holder<T>& rhs) BOOST_NOEXCEPT
  88 {
  89     lhs.swap(rhs);
  90 }
  91
  92 }} // namespace detail::variant
  93 } // namespace boost
  94
  95 #endif // BOOST_VARIANT_DETAIL_BACKUP_HOLDER_HPP