tracked_objects_visitor.hpp 3.2 KB

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  1. // Boost.Signals2 library
  2. // Copyright Frank Mori Hess 2007-2008.
  3. // Copyright Timmo Stange 2007.
  4. // Copyright Douglas Gregor 2001-2004. Use, modification and
  5. // distribution is subject to the Boost Software License, Version
  6. // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  7. // http://www.boost.org/LICENSE_1_0.txt)
  8. // For more information, see http://www.boost.org
  9. #ifndef BOOST_SIGNALS2_TRACKED_OBJECTS_VISITOR_HPP
  10. #define BOOST_SIGNALS2_TRACKED_OBJECTS_VISITOR_HPP
  11. #include <boost/mpl/bool.hpp>
  12. #include <boost/ref.hpp>
  13. #include <boost/signals2/detail/signals_common.hpp>
  14. #include <boost/signals2/slot_base.hpp>
  15. #include <boost/signals2/trackable.hpp>
  16. #include <boost/type_traits/is_function.hpp>
  17. #include <boost/type_traits/is_pointer.hpp>
  18. #include <boost/type_traits/remove_pointer.hpp>
  19. #include <boost/utility/addressof.hpp>
  20. namespace boost
  21. {
  22. namespace signals2
  23. {
  24. namespace detail
  25. {
  26. // Visitor to collect tracked objects from a bound function.
  27. class tracked_objects_visitor
  28. {
  29. public:
  30. tracked_objects_visitor(slot_base *slot) : slot_(slot)
  31. {}
  32. template<typename T>
  33. void operator()(const T& t) const
  34. {
  35. m_visit_reference_wrapper(t, mpl::bool_<is_reference_wrapper<T>::value>());
  36. }
  37. private:
  38. template<typename T>
  39. void m_visit_reference_wrapper(const reference_wrapper<T> &t, const mpl::bool_<true> &) const
  40. {
  41. m_visit_pointer(t.get_pointer(), mpl::bool_<true>());
  42. }
  43. template<typename T>
  44. void m_visit_reference_wrapper(const T &t, const mpl::bool_<false> &) const
  45. {
  46. m_visit_pointer(t, mpl::bool_<is_pointer<T>::value>());
  47. }
  48. template<typename T>
  49. void m_visit_pointer(const T &t, const mpl::bool_<true> &) const
  50. {
  51. m_visit_not_function_pointer(t, mpl::bool_<!is_function<typename remove_pointer<T>::type>::value>());
  52. }
  53. template<typename T>
  54. void m_visit_pointer(const T &t, const mpl::bool_<false> &) const
  55. {
  56. m_visit_pointer(boost::addressof(t), mpl::bool_<true>());
  57. }
  58. template<typename T>
  59. void m_visit_not_function_pointer(const T *t, const mpl::bool_<true> &) const
  60. {
  61. m_visit_signal(t, mpl::bool_<is_signal<T>::value>());
  62. }
  63. template<typename T>
  64. void m_visit_not_function_pointer(const T &, const mpl::bool_<false> &) const
  65. {}
  66. template<typename T>
  67. void m_visit_signal(const T *signal, const mpl::bool_<true> &) const
  68. {
  69. if(signal)
  70. slot_->track_signal(*signal);
  71. }
  72. template<typename T>
  73. void m_visit_signal(const T &t, const mpl::bool_<false> &) const
  74. {
  75. add_if_trackable(t);
  76. }
  77. void add_if_trackable(const trackable *trackable) const
  78. {
  79. if(trackable)
  80. slot_->_tracked_objects.push_back(trackable->get_weak_ptr());
  81. }
  82. void add_if_trackable(const void *) const {}
  83. mutable slot_base * slot_;
  84. };
  85. } // end namespace detail
  86. } // end namespace signals2
  87. } // end namespace boost
  88. #endif // BOOST_SIGNALS2_TRACKED_OBJECTS_VISITOR_HPP