1 // Boost.Signals2 library 2 3 // Copyright Frank Mori Hess 2007,2009. 4 // Copyright Timmo Stange 2007. 5 // Copyright Douglas Gregor 2001-2004. Use, modification and 6 // distribution is subject to the Boost Software License, Version 7 // 1.0. (See accompanying file LICENSE_1_0.txt or copy at 8 // http://www.boost.org/LICENSE_1_0.txt) 9 10 // Compatibility class to ease porting from the original 11 // Boost.Signals library. However, 12 // boost::signals2::trackable is NOT thread-safe. 13 14 // For more information, see http://www.boost.org 15 16 #ifndef BOOST_SIGNALS2_TRACKABLE_HPP 17 #define BOOST_SIGNALS2_TRACKABLE_HPP 18 19 #include <boost/assert.hpp> 20 #include <boost/shared_ptr.hpp> 21 #include <boost/weak_ptr.hpp> 22 23 namespace boost { 24 namespace signals2 { 25 namespace detail 26 { 27 class tracked_objects_visitor; 28 29 // trackable_pointee is used to identify the tracked shared_ptr 30 // originating from the signals2::trackable class. These tracked 31 // shared_ptr are special in that we shouldn't bother to 32 // increment their use count during signal invocation, since 33 // they don't actually control the lifetime of the 34 // signals2::trackable object they are associated with. 35 class trackable_pointee 36 {}; 37 } 38 class trackable { 39 protected: trackable()40 trackable(): _tracked_ptr(static_cast<detail::trackable_pointee*>(0)) {} trackable(const trackable &)41 trackable(const trackable &): _tracked_ptr(static_cast<detail::trackable_pointee*>(0)) {} operator =(const trackable &)42 trackable& operator=(const trackable &) 43 { 44 return *this; 45 } ~trackable()46 ~trackable() {} 47 private: 48 friend class detail::tracked_objects_visitor; get_weak_ptr() const49 weak_ptr<detail::trackable_pointee> get_weak_ptr() const 50 { 51 return _tracked_ptr; 52 } 53 54 shared_ptr<detail::trackable_pointee> _tracked_ptr; 55 }; 56 } // end namespace signals2 57 } // end namespace boost 58 59 #endif // BOOST_SIGNALS2_TRACKABLE_HPP 60