| #ifndef BOOST_SMART_PTR_ENABLE_SHARED_FROM_THIS_HPP_INCLUDED |
| #define BOOST_SMART_PTR_ENABLE_SHARED_FROM_THIS_HPP_INCLUDED |
| |
| // |
| // enable_shared_from_this.hpp |
| // |
| // Copyright 2002, 2009 Peter Dimov |
| // |
| // 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 |
| // |
| // http://www.boost.org/libs/smart_ptr/enable_shared_from_this.html |
| // |
| |
| #include <boost/smart_ptr/weak_ptr.hpp> |
| #include <boost/smart_ptr/shared_ptr.hpp> |
| #include <boost/assert.hpp> |
| #include <boost/config.hpp> |
| |
| namespace boost |
| { |
| |
| template<class T> class enable_shared_from_this |
| { |
| protected: |
| |
| enable_shared_from_this() |
| { |
| } |
| |
| enable_shared_from_this(enable_shared_from_this const &) |
| { |
| } |
| |
| enable_shared_from_this & operator=(enable_shared_from_this const &) |
| { |
| return *this; |
| } |
| |
| ~enable_shared_from_this() |
| { |
| } |
| |
| public: |
| |
| shared_ptr<T> shared_from_this() |
| { |
| shared_ptr<T> p( weak_this_ ); |
| BOOST_ASSERT( p.get() == this ); |
| return p; |
| } |
| |
| shared_ptr<T const> shared_from_this() const |
| { |
| shared_ptr<T const> p( weak_this_ ); |
| BOOST_ASSERT( p.get() == this ); |
| return p; |
| } |
| |
| public: // actually private, but avoids compiler template friendship issues |
| |
| // Note: invoked automatically by shared_ptr; do not call |
| template<class X, class Y> void _internal_accept_owner( shared_ptr<X> const * ppx, Y * py ) const |
| { |
| if( weak_this_.expired() ) |
| { |
| weak_this_ = shared_ptr<T>( *ppx, py ); |
| } |
| } |
| |
| private: |
| |
| mutable weak_ptr<T> weak_this_; |
| }; |
| |
| } // namespace boost |
| |
| #endif // #ifndef BOOST_SMART_PTR_ENABLE_SHARED_FROM_THIS_HPP_INCLUDED |