Chris@16: #ifndef BOOST_ENABLE_SHARED_FROM_RAW_HPP_INCLUDED
Chris@16: #define BOOST_ENABLE_SHARED_FROM_RAW_HPP_INCLUDED
Chris@16: 
Chris@16: //
Chris@16: //  enable_shared_from_raw.hpp
Chris@16: //
Chris@101: //  Copyright 2002, 2009, 2014 Peter Dimov
Chris@16: //  Copyright 2008-2009 Frank Mori Hess
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: 
Chris@16: #include <boost/config.hpp>
Chris@16: #include <boost/shared_ptr.hpp>
Chris@16: #include <boost/weak_ptr.hpp>
Chris@16: #include <boost/assert.hpp>
Chris@16: #include <boost/detail/workaround.hpp>
Chris@16: 
Chris@16: namespace boost
Chris@16: {
Chris@16: template<typename T> boost::shared_ptr<T> shared_from_raw(T *);
Chris@16: template<typename T> boost::weak_ptr<T> weak_from_raw(T *);
Chris@16: 
Chris@16: namespace detail
Chris@16: {
Chris@16: template< class X, class Y > inline void sp_enable_shared_from_this( boost::shared_ptr<X> * ppx, Y const * py, boost::enable_shared_from_raw const * pe );
Chris@16: 
Chris@16: } // namespace detail
Chris@16: 
Chris@16: class enable_shared_from_raw
Chris@16: {
Chris@16: protected:
Chris@16: 
Chris@16:     enable_shared_from_raw()
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     enable_shared_from_raw( enable_shared_from_raw const & )
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     enable_shared_from_raw & operator=( enable_shared_from_raw const & )
Chris@16:     {
Chris@16:         return *this;
Chris@16:     }
Chris@16: 
Chris@16:     ~enable_shared_from_raw()
Chris@16:     {
Chris@16:         BOOST_ASSERT( shared_this_.use_count() <= 1 ); // make sure no dangling shared_ptr objects exist
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16: 
Chris@101:     void init_if_expired() const
Chris@16:     {
Chris@16:         if( weak_this_.expired() )
Chris@16:         {
Chris@16:             shared_this_.reset( static_cast<void*>(0), detail::esft2_deleter_wrapper() );
Chris@16:             weak_this_ = shared_this_;
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@101:     void init_if_empty() const
Chris@101:     {
Chris@101:         if( weak_this_._empty() )
Chris@101:         {
Chris@101:             shared_this_.reset( static_cast<void*>(0), detail::esft2_deleter_wrapper() );
Chris@101:             weak_this_ = shared_this_;
Chris@101:         }
Chris@101:     }
Chris@101: 
Chris@16: #ifdef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
Chris@16: public:
Chris@16: #else
Chris@16: private:
Chris@16:     template<class Y> friend class shared_ptr;
Chris@16:     template<typename T> friend boost::shared_ptr<T> shared_from_raw(T *);
Chris@16:     template<typename T> friend boost::weak_ptr<T> weak_from_raw(T *);
Chris@16:     template< class X, class Y > friend inline void detail::sp_enable_shared_from_this( boost::shared_ptr<X> * ppx, Y const * py, boost::enable_shared_from_raw const * pe );
Chris@16: #endif
Chris@16: 
Chris@101:     shared_ptr<void const volatile> shared_from_this() const
Chris@16:     {
Chris@101:         init_if_expired();
Chris@101:         return shared_ptr<void const volatile>( weak_this_ );
Chris@16:     }
Chris@16: 
Chris@101:     shared_ptr<void const volatile> shared_from_this() const volatile
Chris@16:     {
Chris@101:         return const_cast< enable_shared_from_raw const * >( this )->shared_from_this();
Chris@101:     }
Chris@101: 
Chris@101:     weak_ptr<void const volatile> weak_from_this() const
Chris@101:     {
Chris@101:         init_if_empty();
Chris@101:         return weak_this_;
Chris@101:     }
Chris@101: 
Chris@101:     weak_ptr<void const volatile> weak_from_this() const volatile
Chris@101:     {
Chris@101:         return const_cast< enable_shared_from_raw const * >( this )->weak_from_this();
Chris@16:     }
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> * ppx, Y * py ) const
Chris@16:     {
Chris@16:         BOOST_ASSERT( ppx != 0 );
Chris@16: 
Chris@16:         if( weak_this_.expired() )
Chris@16:         {
Chris@16:             weak_this_ = *ppx;
Chris@16:         }
Chris@16:         else if( shared_this_.use_count() != 0 )
Chris@16:         {
Chris@16:             BOOST_ASSERT( ppx->unique() ); // no weak_ptrs should exist either, but there's no way to check that
Chris@16: 
Chris@16:             detail::esft2_deleter_wrapper * pd = boost::get_deleter<detail::esft2_deleter_wrapper>( shared_this_ );
Chris@16:             BOOST_ASSERT( pd != 0 );
Chris@16: 
Chris@16:             pd->set_deleter( *ppx );
Chris@16: 
Chris@16:             ppx->reset( shared_this_, ppx->get() );
Chris@16:             shared_this_.reset();
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@101:     mutable weak_ptr<void const volatile> weak_this_;
Chris@101: 
Chris@16: private:
Chris@101: 
Chris@101:     mutable shared_ptr<void const volatile> shared_this_;
Chris@16: };
Chris@16: 
Chris@16: template<typename T>
Chris@16: boost::shared_ptr<T> shared_from_raw(T *p)
Chris@16: {
Chris@16:     BOOST_ASSERT(p != 0);
Chris@16:     return boost::shared_ptr<T>(p->enable_shared_from_raw::shared_from_this(), p);
Chris@16: }
Chris@16: 
Chris@16: template<typename T>
Chris@16: boost::weak_ptr<T> weak_from_raw(T *p)
Chris@16: {
Chris@16:     BOOST_ASSERT(p != 0);
Chris@16:     boost::weak_ptr<T> result;
Chris@101:     result._internal_aliasing_assign(p->enable_shared_from_raw::weak_from_this(), p);
Chris@16:     return result;
Chris@16: }
Chris@16: 
Chris@16: namespace detail
Chris@16: {
Chris@16:     template< class X, class Y > inline void sp_enable_shared_from_this( boost::shared_ptr<X> * ppx, Y const * py, boost::enable_shared_from_raw const * pe )
Chris@16:     {
Chris@16:         if( pe != 0 )
Chris@16:         {
Chris@16:             pe->_internal_accept_owner( ppx, const_cast< Y* >( py ) );
Chris@16:         }
Chris@16:     }
Chris@16: } // namepsace detail
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif  // #ifndef BOOST_ENABLE_SHARED_FROM_RAW_HPP_INCLUDED