| #ifndef BOOST_ENABLE_SHARED_FROM_RAW_HPP_INCLUDED |
| #define BOOST_ENABLE_SHARED_FROM_RAW_HPP_INCLUDED |
| |
| // |
| // enable_shared_from_raw.hpp |
| // |
| // Copyright 2002, 2009, 2014 Peter Dimov |
| // Copyright 2008-2009 Frank Mori Hess |
| // |
| // Distributed under the Boost Software License, Version 1.0. |
| // See accompanying file LICENSE_1_0.txt or copy at |
| // http://www.boost.org/LICENSE_1_0.txt |
| // |
| |
| #include <boost/config.hpp> |
| #include <boost/shared_ptr.hpp> |
| #include <boost/weak_ptr.hpp> |
| #include <boost/assert.hpp> |
| #include <boost/config/workaround.hpp> |
| |
| namespace boost |
| { |
| template<typename T> boost::shared_ptr<T> shared_from_raw(T *); |
| template<typename T> boost::weak_ptr<T> weak_from_raw(T *); |
| |
| namespace detail |
| { |
| 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 ); |
| |
| } // namespace detail |
| |
| class enable_shared_from_raw |
| { |
| protected: |
| |
| enable_shared_from_raw() |
| { |
| } |
| |
| enable_shared_from_raw( enable_shared_from_raw const & ) |
| { |
| } |
| |
| enable_shared_from_raw & operator=( enable_shared_from_raw const & ) |
| { |
| return *this; |
| } |
| |
| ~enable_shared_from_raw() |
| { |
| BOOST_ASSERT( shared_this_.use_count() <= 1 ); // make sure no dangling shared_ptr objects exist |
| } |
| |
| private: |
| |
| void init_if_expired() const |
| { |
| if( weak_this_.expired() ) |
| { |
| shared_this_.reset( static_cast<void*>(0), detail::esft2_deleter_wrapper() ); |
| weak_this_ = shared_this_; |
| } |
| } |
| |
| void init_if_empty() const |
| { |
| if( weak_this_._empty() ) |
| { |
| shared_this_.reset( static_cast<void*>(0), detail::esft2_deleter_wrapper() ); |
| weak_this_ = shared_this_; |
| } |
| } |
| |
| #ifdef BOOST_NO_MEMBER_TEMPLATE_FRIENDS |
| public: |
| #else |
| private: |
| template<class Y> friend class shared_ptr; |
| template<typename T> friend boost::shared_ptr<T> shared_from_raw(T *); |
| template<typename T> friend boost::weak_ptr<T> weak_from_raw(T *); |
| 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 ); |
| #endif |
| |
| shared_ptr<void const volatile> shared_from_this() const |
| { |
| init_if_expired(); |
| return shared_ptr<void const volatile>( weak_this_ ); |
| } |
| |
| shared_ptr<void const volatile> shared_from_this() const volatile |
| { |
| return const_cast< enable_shared_from_raw const * >( this )->shared_from_this(); |
| } |
| |
| weak_ptr<void const volatile> weak_from_this() const |
| { |
| init_if_empty(); |
| return weak_this_; |
| } |
| |
| weak_ptr<void const volatile> weak_from_this() const volatile |
| { |
| return const_cast< enable_shared_from_raw const * >( this )->weak_from_this(); |
| } |
| |
| // Note: invoked automatically by shared_ptr; do not call |
| template<class X, class Y> void _internal_accept_owner( shared_ptr<X> * ppx, Y * ) const |
| { |
| BOOST_ASSERT( ppx != 0 ); |
| |
| if( weak_this_.expired() ) |
| { |
| weak_this_ = *ppx; |
| } |
| else if( shared_this_.use_count() != 0 ) |
| { |
| BOOST_ASSERT( ppx->unique() ); // no weak_ptrs should exist either, but there's no way to check that |
| |
| detail::esft2_deleter_wrapper * pd = boost::get_deleter<detail::esft2_deleter_wrapper>( shared_this_ ); |
| BOOST_ASSERT( pd != 0 ); |
| |
| pd->set_deleter( *ppx ); |
| |
| ppx->reset( shared_this_, ppx->get() ); |
| shared_this_.reset(); |
| } |
| } |
| |
| mutable weak_ptr<void const volatile> weak_this_; |
| |
| private: |
| |
| mutable shared_ptr<void const volatile> shared_this_; |
| }; |
| |
| template<typename T> |
| boost::shared_ptr<T> shared_from_raw(T *p) |
| { |
| BOOST_ASSERT(p != 0); |
| return boost::shared_ptr<T>(p->enable_shared_from_raw::shared_from_this(), p); |
| } |
| |
| template<typename T> |
| boost::weak_ptr<T> weak_from_raw(T *p) |
| { |
| BOOST_ASSERT(p != 0); |
| boost::weak_ptr<T> result(p->enable_shared_from_raw::weak_from_this(), p); |
| return result; |
| } |
| |
| namespace detail |
| { |
| 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 ) |
| { |
| if( pe != 0 ) |
| { |
| pe->_internal_accept_owner( ppx, const_cast< Y* >( py ) ); |
| } |
| } |
| } // namepsace detail |
| |
| } // namespace boost |
| |
| #endif // #ifndef BOOST_ENABLE_SHARED_FROM_RAW_HPP_INCLUDED |