1 // Boost.Signals2 library 2 3 // Copyright Frank Mori Hess 2007-2008. 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 // For more information, see http://www.boost.org 11 12 #ifndef BOOST_SIGNALS2_TRACKED_OBJECTS_VISITOR_HPP 13 #define BOOST_SIGNALS2_TRACKED_OBJECTS_VISITOR_HPP 14 15 #include <boost/mpl/bool.hpp> 16 #include <boost/ref.hpp> 17 #include <boost/signals2/detail/signals_common.hpp> 18 #include <boost/signals2/slot_base.hpp> 19 #include <boost/signals2/trackable.hpp> 20 #include <boost/type_traits/is_function.hpp> 21 #include <boost/type_traits/is_pointer.hpp> 22 #include <boost/type_traits/remove_pointer.hpp> 23 #include <boost/utility/addressof.hpp> 24 25 namespace boost 26 { 27 namespace signals2 28 { 29 namespace detail 30 { 31 // Visitor to collect tracked objects from a bound function. 32 class tracked_objects_visitor 33 { 34 public: tracked_objects_visitor(slot_base * slot)35 tracked_objects_visitor(slot_base *slot) : slot_(slot) 36 {} 37 template<typename T> operator ()(const T & t) const38 void operator()(const T& t) const 39 { 40 m_visit_reference_wrapper(t, mpl::bool_<is_reference_wrapper<T>::value>()); 41 } 42 private: 43 template<typename T> m_visit_reference_wrapper(const reference_wrapper<T> & t,const mpl::bool_<true> &) const44 void m_visit_reference_wrapper(const reference_wrapper<T> &t, const mpl::bool_<true> &) const 45 { 46 m_visit_pointer(t.get_pointer(), mpl::bool_<true>()); 47 } 48 template<typename T> m_visit_reference_wrapper(const T & t,const mpl::bool_<false> &) const49 void m_visit_reference_wrapper(const T &t, const mpl::bool_<false> &) const 50 { 51 m_visit_pointer(t, mpl::bool_<is_pointer<T>::value>()); 52 } 53 template<typename T> m_visit_pointer(const T & t,const mpl::bool_<true> &) const54 void m_visit_pointer(const T &t, const mpl::bool_<true> &) const 55 { 56 m_visit_not_function_pointer(t, mpl::bool_<!is_function<typename remove_pointer<T>::type>::value>()); 57 } 58 template<typename T> m_visit_pointer(const T & t,const mpl::bool_<false> &) const59 void m_visit_pointer(const T &t, const mpl::bool_<false> &) const 60 { 61 m_visit_pointer(boost::addressof(t), mpl::bool_<true>()); 62 } 63 template<typename T> m_visit_not_function_pointer(const T * t,const mpl::bool_<true> &) const64 void m_visit_not_function_pointer(const T *t, const mpl::bool_<true> &) const 65 { 66 m_visit_signal(t, mpl::bool_<is_signal<T>::value>()); 67 } 68 template<typename T> m_visit_not_function_pointer(const T &,const mpl::bool_<false> &) const69 void m_visit_not_function_pointer(const T &, const mpl::bool_<false> &) const 70 {} 71 template<typename T> m_visit_signal(const T * signal,const mpl::bool_<true> &) const72 void m_visit_signal(const T *signal, const mpl::bool_<true> &) const 73 { 74 if(signal) 75 slot_->track_signal(*signal); 76 } 77 template<typename T> m_visit_signal(const T & t,const mpl::bool_<false> &) const78 void m_visit_signal(const T &t, const mpl::bool_<false> &) const 79 { 80 add_if_trackable(t); 81 } add_if_trackable(const trackable * trackable) const82 void add_if_trackable(const trackable *trackable) const 83 { 84 if(trackable) 85 slot_->_tracked_objects.push_back(trackable->get_weak_ptr()); 86 } add_if_trackable(const void *) const87 void add_if_trackable(const void *) const {} 88 89 mutable slot_base * slot_; 90 }; 91 92 93 } // end namespace detail 94 } // end namespace signals2 95 } // end namespace boost 96 97 #endif // BOOST_SIGNALS2_TRACKED_OBJECTS_VISITOR_HPP 98 99