1// Boost.Signals library
2
3// Copyright Douglas Gregor 2001-2004. Use, modification and
4// distribution is subject to the Boost Software License, Version
5// 1.0. (See accompanying file LICENSE_1_0.txt or copy at
6// http://www.boost.org/LICENSE_1_0.txt)
7
8// For more information, see http://www.boost.org
9
10#ifndef BOOST_SIGNALS_TRACKABLE_HPP
11#define BOOST_SIGNALS_TRACKABLE_HPP
12
13#include <boost/type_traits.hpp>
14#include <boost/signals/connection.hpp>
15#include <boost/ref.hpp>
16#include <boost/utility/addressof.hpp>
17#include <list>
18#include <vector>
19
20#ifdef BOOST_HAS_ABI_HEADERS
21# include BOOST_ABI_PREFIX
22#endif
23
24namespace boost {
25
26namespace BOOST_SIGNALS_NAMESPACE {
27 // Base class for "trackable" objects that can be tracked when they are
28 // bound in slot target functions. When a trackable object is destroyed,
29 // the signal/slot connections are disconnected automatically.
30 class BOOST_SIGNALS_DECL trackable {
31 private:
32 static void signal_disconnected(void* obj, void* data);
33
34 friend class detail::signal_base_impl;
35 friend class detail::slot_base;
36 void signal_connected(connection, BOOST_SIGNALS_NAMESPACE::detail::bound_object&) const;
37
38 protected:
39 trackable() : connected_signals(), dying(false) {}
40 trackable(const trackable&) : connected_signals(), dying(false) {}
41 ~trackable();
42
43 trackable& operator=(const trackable&)
44 {
45 dying = true;
46 connected_signals.clear();
47 dying = false;
48 return *this;
49 }
50
51 private:
52 typedef std::list<connection> connection_list;
53 typedef connection_list::iterator connection_iterator;
54
55 // List of connections that this object is part of
56 mutable connection_list connected_signals;
57
58 // True when the object is being destroyed
59 mutable bool dying;
60 };
61
62 namespace detail {
63 template<bool Cond> struct truth {};
64
65 // A visitor that adds each trackable object to a vector
66 class bound_objects_visitor {
67 public:
68 bound_objects_visitor(std::vector<const trackable*>& v) :
69 bound_objects(v)
70 {
71 }
72
73 template<typename T>
74 void operator()(const T& t) const
75 {
76 decode(t, 0);
77 }
78
79 private:
80 // decode() decides between a reference wrapper and anything else
81 template<typename T>
82 void decode(const reference_wrapper<T>& t, int) const
83 {
84 add_if_trackable(t.get_pointer());
85 }
86
87 template<typename T>
88 void decode(const T& t, long) const
89 {
90 typedef truth<(is_pointer<T>::value)> is_a_pointer;
91 maybe_get_pointer(t, is_a_pointer());
92 }
93
94 // maybe_get_pointer() decides between a pointer and a non-pointer
95 template<typename T>
96 void maybe_get_pointer(const T& t, truth<true>) const
97 {
98 add_if_trackable(t);
99 }
100
101 template<typename T>
102 void maybe_get_pointer(const T& t, truth<false>) const
103 {
104 // Take the address of this object, because the object itself may be
105 // trackable
106 add_if_trackable(boost::addressof(t));
107 }
108
109 // add_if_trackable() adds trackable objects to the list of bound objects
110 inline void add_if_trackable(const trackable* b) const
111 {
112 if (b) {
113 bound_objects.push_back(x: b);
114 }
115 }
116
117 inline void add_if_trackable(const void*) const { }
118
119 template<typename R>
120 inline void add_if_trackable(R (*)()) const { }
121
122 template<typename R, typename T1>
123 inline void add_if_trackable(R (*)(T1)) const { }
124
125 template<typename R, typename T1, typename T2>
126 inline void add_if_trackable(R (*)(T1, T2)) const { }
127
128 template<typename R, typename T1, typename T2, typename T3>
129 inline void add_if_trackable(R (*)(T1, T2, T3)) const { }
130
131 template<typename R, typename T1, typename T2, typename T3, typename T4>
132 inline void add_if_trackable(R (*)(T1, T2, T3, T4)) const { }
133
134 template<typename R, typename T1, typename T2, typename T3, typename T4,
135 typename T5>
136 inline void add_if_trackable(R (*)(T1, T2, T3, T4, T5)) const { }
137
138 template<typename R, typename T1, typename T2, typename T3, typename T4,
139 typename T5, typename T6>
140 inline void add_if_trackable(R (*)(T1, T2, T3, T4, T5, T6)) const { }
141
142 template<typename R, typename T1, typename T2, typename T3, typename T4,
143 typename T5, typename T6, typename T7>
144 inline void add_if_trackable(R (*)(T1, T2, T3, T4, T5, T6, T7)) const { }
145
146 template<typename R, typename T1, typename T2, typename T3, typename T4,
147 typename T5, typename T6, typename T7, typename T8>
148 inline void
149 add_if_trackable(R (*)(T1, T2, T3, T4, T5, T6, T7, T8)) const { }
150
151 template<typename R, typename T1, typename T2, typename T3, typename T4,
152 typename T5, typename T6, typename T7, typename T8, typename T9>
153 inline void
154 add_if_trackable(R (*)(T1, T2, T3, T4, T5, T6, T7, T8, T9)) const { }
155
156 template<typename R, typename T1, typename T2, typename T3, typename T4,
157 typename T5, typename T6, typename T7, typename T8, typename T9,
158 typename T10>
159 inline void
160 add_if_trackable(R (*)(T1, T2, T3, T4, T5, T6, T7, T8, T9, T10)) const { }
161
162 std::vector<const trackable*>& bound_objects;
163 };
164 } // end namespace detail
165} // end namespace BOOST_SIGNALS_NAMESPACE
166
167} // end namespace boost
168
169#ifdef BOOST_HAS_ABI_HEADERS
170# include BOOST_ABI_SUFFIX
171#endif
172
173#endif // BOOST_SIGNALS_TRACKABLE_HPP
174

source code of boost/boost/signals/trackable.hpp