Chris@16: #ifndef BOOST_SMART_PTR_ENABLE_SHARED_FROM_THIS_HPP_INCLUDED
Chris@16: #define BOOST_SMART_PTR_ENABLE_SHARED_FROM_THIS_HPP_INCLUDED
Chris@16: 
Chris@16: //
Chris@16: //  enable_shared_from_this.hpp
Chris@16: //
Chris@16: //  Copyright 2002, 2009 Peter Dimov
Chris@16: //
Chris@16: //  Distributed under the Boost Software License, Version 1.0.
Chris@16: //  See accompanying file LICENSE_1_0.txt or copy at
Chris@16: //  http://www.boost.org/LICENSE_1_0.txt
Chris@16: //
Chris@16: //  http://www.boost.org/libs/smart_ptr/enable_shared_from_this.html
Chris@16: //
Chris@16: 
Chris@16: #include <boost/smart_ptr/weak_ptr.hpp>
Chris@16: #include <boost/smart_ptr/shared_ptr.hpp>
Chris@16: #include <boost/assert.hpp>
Chris@16: #include <boost/config.hpp>
Chris@16: 
Chris@16: namespace boost
Chris@16: {
Chris@16: 
Chris@16: template<class T> class enable_shared_from_this
Chris@16: {
Chris@16: protected:
Chris@16: 
Chris@16:     enable_shared_from_this() BOOST_NOEXCEPT
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     enable_shared_from_this(enable_shared_from_this const &) BOOST_NOEXCEPT
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     enable_shared_from_this & operator=(enable_shared_from_this const &) BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         return *this;
Chris@16:     }
Chris@16: 
Chris@16:     ~enable_shared_from_this() BOOST_NOEXCEPT // ~weak_ptr<T> newer throws, so this call also must not throw
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16: public:
Chris@16: 
Chris@16:     shared_ptr<T> shared_from_this()
Chris@16:     {
Chris@16:         shared_ptr<T> p( weak_this_ );
Chris@16:         BOOST_ASSERT( p.get() == this );
Chris@16:         return p;
Chris@16:     }
Chris@16: 
Chris@16:     shared_ptr<T const> shared_from_this() const
Chris@16:     {
Chris@16:         shared_ptr<T const> p( weak_this_ );
Chris@16:         BOOST_ASSERT( p.get() == this );
Chris@16:         return p;
Chris@16:     }
Chris@16: 
Chris@101:     weak_ptr<T> weak_from_this() BOOST_NOEXCEPT
Chris@101:     {
Chris@101:         return weak_this_;
Chris@101:     }
Chris@101: 
Chris@101:     weak_ptr<T const> weak_from_this() const BOOST_NOEXCEPT
Chris@101:     {
Chris@101:         return weak_this_;
Chris@101:     }
Chris@101: 
Chris@16: public: // actually private, but avoids compiler template friendship issues
Chris@16: 
Chris@16:     // Note: invoked automatically by shared_ptr; do not call
Chris@16:     template<class X, class Y> void _internal_accept_owner( shared_ptr<X> const * ppx, Y * py ) const
Chris@16:     {
Chris@16:         if( weak_this_.expired() )
Chris@16:         {
Chris@16:             weak_this_ = shared_ptr<T>( *ppx, py );
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16: 
Chris@16:     mutable weak_ptr<T> weak_this_;
Chris@16: };
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif  // #ifndef BOOST_SMART_PTR_ENABLE_SHARED_FROM_THIS_HPP_INCLUDED