ceph/src/boost/boost/xpressive/detail/utility/save_restore.hpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // save_restore.hpp
   3 //
   4 //  Copyright 2008 Eric Niebler. Distributed under the Boost
   5 //  Software License, Version 1.0. (See accompanying file
   6 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7
   8 #ifndef BOOST_XPRESSIVE_DETAIL_UTILITY_SAVE_RESTORE_HPP_EAN_10_04_2005
   9 #define BOOST_XPRESSIVE_DETAIL_UTILITY_SAVE_RESTORE_HPP_EAN_10_04_2005
  10
  11 // MS compatible compilers support #pragma once
  12 #if defined(_MSC_VER)
  13 # pragma once
  14 #endif
  15
  16 #include <boost/noncopyable.hpp>
  17
  18 namespace boost { namespace xpressive { namespace detail
  19 {
  20
  21     template<typename T>
  22     struct save_restore
  23       : private noncopyable
  24     {
  25         explicit save_restore(T &t)
  26           : ref(t)
  27           , val(t)
  28         {
  29         }
  30
  31         save_restore(T &t, T const &n)
  32           : ref(t)
  33           , val(t)
  34         {
  35             this->ref = n;
  36         }
  37
  38         ~save_restore()
  39         {
  40             this->ref = this->val;
  41         }
  42
  43         void restore()
  44         {
  45             this->ref = this->val;
  46         }
  47
  48     private:
  49         T &ref;
  50         T const val;
  51     };
  52
  53 }}}
  54
  55 #endif