ceph/src/boost/libs/interprocess/include/boost/interprocess/smart_ptr/enable_shared_from_this.hpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 //
   3 // This file is the adaptation for Interprocess of boost/enable_shared_from_this.hpp
   4 //
   5 // (C) Copyright Peter Dimov 2002
   6 // (C) Copyright Ion Gaztanaga 2006-2012. Distributed under the Boost
   7 // Software License, Version 1.0. (See accompanying file
   8 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   9 //
  10 // See http://www.boost.org/libs/interprocess for documentation.
  11 //
  12 //////////////////////////////////////////////////////////////////////////////
  13
  14 #ifndef BOOST_INTERPROCESS_ENABLE_SHARED_FROM_THIS_HPP_INCLUDED
  15 #define BOOST_INTERPROCESS_ENABLE_SHARED_FROM_THIS_HPP_INCLUDED
  16
  17 #ifndef BOOST_CONFIG_HPP
  18 #  include <boost/config.hpp>
  19 #endif
  20 #
  21 #if defined(BOOST_HAS_PRAGMA_ONCE)
  22 #  pragma once
  23 #endif
  24
  25 #include <boost/interprocess/detail/config_begin.hpp>
  26 #include <boost/interprocess/detail/workaround.hpp>
  27
  28 #include <boost/assert.hpp>
  29 #include <boost/interprocess/smart_ptr/weak_ptr.hpp>
  30 #include <boost/interprocess/smart_ptr/shared_ptr.hpp>
  31
  32 //!\file
  33 //!Describes an utility to form a shared pointer from this
  34
  35 namespace boost{
  36 namespace interprocess{
  37
  38 //!This class is used as a base class that allows a shared_ptr to the current
  39 //!object to be obtained from within a member function.
  40 //!enable_shared_from_this defines two member functions called shared_from_this
  41 //!that return a shared_ptr<T> and shared_ptr<T const>, depending on constness, to this.
  42 template<class T, class A, class D>
  43 class enable_shared_from_this
  44 {
  45    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
  46    protected:
  47    enable_shared_from_this()
  48    {}
  49
  50    enable_shared_from_this(enable_shared_from_this const &)
  51    {}
  52
  53    enable_shared_from_this & operator=(enable_shared_from_this const &)
  54    {  return *this;  }
  55
  56    ~enable_shared_from_this()
  57    {}
  58    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
  59
  60    public:
  61    shared_ptr<T, A, D> shared_from_this()
  62    {
  63       shared_ptr<T, A, D> p(_internal_weak_this);
  64       BOOST_ASSERT(ipcdetail::to_raw_pointer(p.get()) == this);
  65       return p;
  66    }
  67
  68    shared_ptr<T const, A, D> shared_from_this() const
  69    {
  70       shared_ptr<T const, A, D> p(_internal_weak_this);
  71       BOOST_ASSERT(ipcdetail::to_raw_pointer(p.get()) == this);
  72       return p;
  73    }
  74
  75    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
  76    typedef T element_type;
  77    mutable weak_ptr<element_type, A, D> _internal_weak_this;
  78    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
  79 };
  80
  81 } // namespace interprocess
  82 } // namespace boost
  83
  84 #include <boost/interprocess/detail/config_end.hpp>
  85
  86 #endif  // #ifndef BOOST_INTERPROCESS_ENABLE_SHARED_FROM_THIS_HPP_INCLUDED
  87