Chris@16: // Boost.Signals2 library
Chris@16: 
Chris@16: // Copyright Frank Mori Hess 2007,2009.
Chris@16: // Copyright Timmo Stange 2007.
Chris@16: // Copyright Douglas Gregor 2001-2004. Use, modification and
Chris@16: // distribution is subject to the Boost Software License, Version
Chris@16: // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: // Compatibility class to ease porting from the original
Chris@16: // Boost.Signals library.  However,
Chris@16: // boost::signals2::trackable is NOT thread-safe.
Chris@16: 
Chris@16: // For more information, see http://www.boost.org
Chris@16: 
Chris@16: #ifndef BOOST_SIGNALS2_TRACKABLE_HPP
Chris@16: #define BOOST_SIGNALS2_TRACKABLE_HPP
Chris@16: 
Chris@16: #include <boost/assert.hpp>
Chris@16: #include <boost/shared_ptr.hpp>
Chris@101: #include <boost/weak_ptr.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16:   namespace signals2 {
Chris@16:     namespace detail
Chris@16:     {
Chris@16:         class tracked_objects_visitor;
Chris@101:         
Chris@101:         // trackable_pointee is used to identify the tracked shared_ptr 
Chris@101:         // originating from the signals2::trackable class.  These tracked
Chris@101:         // shared_ptr are special in that we shouldn't bother to
Chris@101:         // increment their use count during signal invocation, since
Chris@101:         // they don't actually control the lifetime of the
Chris@101:         // signals2::trackable object they are associated with.
Chris@101:         class trackable_pointee
Chris@101:         {};
Chris@16:     }
Chris@16:     class trackable {
Chris@16:     protected:
Chris@101:       trackable(): _tracked_ptr(static_cast<detail::trackable_pointee*>(0)) {}
Chris@101:       trackable(const trackable &): _tracked_ptr(static_cast<detail::trackable_pointee*>(0)) {}
Chris@16:       trackable& operator=(const trackable &)
Chris@16:       {
Chris@16:           return *this;
Chris@16:       }
Chris@16:       ~trackable() {}
Chris@16:     private:
Chris@16:       friend class detail::tracked_objects_visitor;
Chris@101:       weak_ptr<detail::trackable_pointee> get_weak_ptr() const
Chris@16:       {
Chris@16:           return _tracked_ptr;
Chris@16:       }
Chris@16: 
Chris@101:       shared_ptr<detail::trackable_pointee> _tracked_ptr;
Chris@16:     };
Chris@16:   } // end namespace signals2
Chris@16: } // end namespace boost
Chris@16: 
Chris@16: #endif // BOOST_SIGNALS2_TRACKABLE_HPP