1//=======================================================================
2// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
3// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
4//
5// Distributed under the Boost Software License, Version 1.0. (See
6// accompanying file LICENSE_1_0.txt or copy at
7// http://www.boost.org/LICENSE_1_0.txt)
8//=======================================================================
9//
10// Revision History:
11// 01 April 2001: Modified to use new <boost/limits.hpp> header. (JMaddock)
12//
13#ifndef BOOST_GRAPH_GRAPH_SEARCH_VISITORS_HPP
14#define BOOST_GRAPH_GRAPH_SEARCH_VISITORS_HPP
15
16#include <iosfwd>
17#include <boost/config.hpp>
18#include <boost/type_traits/is_same.hpp>
19#include <boost/mpl/bool.hpp>
20#include <boost/property_map/property_map.hpp>
21#include <boost/graph/graph_traits.hpp>
22#include <boost/limits.hpp>
23
24namespace boost {
25
26 // This is a bit more convenient than std::numeric_limits because
27 // you don't have to explicitly provide type T.
28 template <class T>
29 inline T numeric_limits_max(T) { return (std::numeric_limits<T>::max)(); }
30
31 //========================================================================
32 // Event Tags
33
34 namespace detail {
35 // For partial specialization workaround
36 enum event_visitor_enum
37 { on_no_event_num,
38 on_initialize_vertex_num, on_start_vertex_num,
39 on_discover_vertex_num, on_finish_vertex_num, on_examine_vertex_num,
40 on_examine_edge_num, on_tree_edge_num, on_non_tree_edge_num,
41 on_gray_target_num, on_black_target_num,
42 on_forward_or_cross_edge_num, on_back_edge_num, on_finish_edge_num,
43 on_edge_relaxed_num, on_edge_not_relaxed_num,
44 on_edge_minimized_num, on_edge_not_minimized_num
45 };
46
47 template<typename Event, typename Visitor>
48 struct functor_to_visitor : Visitor
49 {
50 typedef Event event_filter;
51 functor_to_visitor(const Visitor& visitor) : Visitor(visitor) {}
52 };
53
54 } // namespace detail
55
56 struct on_no_event { enum { num = detail::on_no_event_num }; };
57
58 struct on_initialize_vertex {
59 enum { num = detail::on_initialize_vertex_num }; };
60 struct on_start_vertex { enum { num = detail::on_start_vertex_num }; };
61 struct on_discover_vertex { enum { num = detail::on_discover_vertex_num }; };
62 struct on_examine_vertex { enum { num = detail::on_examine_vertex_num }; };
63 struct on_finish_vertex { enum { num = detail::on_finish_vertex_num }; };
64
65 struct on_examine_edge { enum { num = detail::on_examine_edge_num }; };
66 struct on_tree_edge { enum { num = detail::on_tree_edge_num }; };
67 struct on_non_tree_edge { enum { num = detail::on_non_tree_edge_num }; };
68 struct on_gray_target { enum { num = detail::on_gray_target_num }; };
69 struct on_black_target { enum { num = detail::on_black_target_num }; };
70 struct on_forward_or_cross_edge {
71 enum { num = detail::on_forward_or_cross_edge_num }; };
72 struct on_back_edge { enum { num = detail::on_back_edge_num }; };
73 struct on_finish_edge { enum { num = detail::on_finish_edge_num }; };
74
75 struct on_edge_relaxed { enum { num = detail::on_edge_relaxed_num }; };
76 struct on_edge_not_relaxed {
77 enum { num = detail::on_edge_not_relaxed_num }; };
78 struct on_edge_minimized { enum { num = detail::on_edge_minimized_num }; };
79 struct on_edge_not_minimized {
80 enum { num = detail::on_edge_not_minimized_num }; };
81
82 //========================================================================
83 // base_visitor and null_visitor
84
85 // needed for MSVC workaround
86 template <class Visitor>
87 struct base_visitor {
88 typedef on_no_event event_filter;
89 template <class T, class Graph>
90 void operator()(T, Graph&) { }
91 };
92
93 struct null_visitor : public base_visitor<null_visitor> {
94 typedef on_no_event event_filter;
95 template <class T, class Graph>
96 void operator()(T, Graph&) { }
97 };
98
99 //========================================================================
100 // The invoke_visitors() function
101
102 namespace detail {
103 template <class Visitor, class T, class Graph>
104 inline void invoke_dispatch(Visitor& v, T x, Graph& g, mpl::true_) {
105 v(x, g);
106 }
107
108 template <class Visitor, class T, class Graph>
109 inline void invoke_dispatch(Visitor&, T, Graph&, mpl::false_)
110 { }
111 } // namespace detail
112
113 template <class Visitor, class Rest, class T, class Graph, class Tag>
114 inline void
115 invoke_visitors(std::pair<Visitor, Rest>& vlist, T x, Graph& g, Tag tag) {
116 typedef typename Visitor::event_filter Category;
117 typedef typename is_same<Category, Tag>::type IsSameTag;
118 detail::invoke_dispatch(vlist.first, x, g, IsSameTag());
119 invoke_visitors(vlist.second, x, g, tag);
120 }
121 template <class Visitor, class T, class Graph, class Tag>
122 inline void
123 invoke_visitors(Visitor& v, T x, Graph& g, Tag) {
124 typedef typename Visitor::event_filter Category;
125 typedef typename is_same<Category, Tag>::type IsSameTag;
126 detail::invoke_dispatch(v, x, g, IsSameTag());
127 }
128
129 //========================================================================
130 // predecessor_recorder
131
132 template <class PredecessorMap, class Tag>
133 struct predecessor_recorder
134 : public base_visitor<predecessor_recorder<PredecessorMap, Tag> >
135 {
136 typedef Tag event_filter;
137 predecessor_recorder(PredecessorMap pa) : m_predecessor(pa) { }
138 template <class Edge, class Graph>
139 void operator()(Edge e, const Graph& g) {
140 put(m_predecessor, target(e, g), source(e, g));
141 }
142 PredecessorMap m_predecessor;
143 };
144 template <class PredecessorMap, class Tag>
145 predecessor_recorder<PredecessorMap, Tag>
146 record_predecessors(PredecessorMap pa, Tag) {
147 return predecessor_recorder<PredecessorMap, Tag> (pa);
148 }
149
150 //========================================================================
151 // edge_predecessor_recorder
152
153 template <class PredEdgeMap, class Tag>
154 struct edge_predecessor_recorder
155 : public base_visitor<edge_predecessor_recorder<PredEdgeMap, Tag> >
156 {
157 typedef Tag event_filter;
158 edge_predecessor_recorder(PredEdgeMap pa) : m_predecessor(pa) { }
159 template <class Edge, class Graph>
160 void operator()(Edge e, const Graph& g) {
161 put(m_predecessor, target(e, g), e);
162 }
163 PredEdgeMap m_predecessor;
164 };
165 template <class PredEdgeMap, class Tag>
166 edge_predecessor_recorder<PredEdgeMap, Tag>
167 record_edge_predecessors(PredEdgeMap pa, Tag) {
168 return edge_predecessor_recorder<PredEdgeMap, Tag> (pa);
169 }
170
171 //========================================================================
172 // distance_recorder
173
174 template <class DistanceMap, class Tag>
175 struct distance_recorder
176 : public base_visitor<distance_recorder<DistanceMap, Tag> >
177 {
178 typedef Tag event_filter;
179 distance_recorder(DistanceMap pa) : m_distance(pa) { }
180 template <class Edge, class Graph>
181 void operator()(Edge e, const Graph& g) {
182 typename graph_traits<Graph>::vertex_descriptor
183 u = source(e, g), v = target(e, g);
184 put(m_distance, v, get(m_distance, u) + 1);
185 }
186 DistanceMap m_distance;
187 };
188 template <class DistanceMap, class Tag>
189 distance_recorder<DistanceMap, Tag>
190 record_distances(DistanceMap pa, Tag) {
191 return distance_recorder<DistanceMap, Tag> (pa);
192 }
193
194 //========================================================================
195 // time_stamper
196
197
198 template <class TimeMap, class TimeT, class Tag>
199 struct time_stamper
200 : public base_visitor<time_stamper<TimeMap, TimeT, Tag> >
201 {
202 typedef Tag event_filter;
203 time_stamper(TimeMap pa, TimeT& t) : m_time_pa(pa), m_time(t) { }
204 template <class Vertex, class Graph>
205 void operator()(Vertex u, const Graph&) {
206 put(m_time_pa, u, ++m_time);
207 }
208 TimeMap m_time_pa;
209 TimeT& m_time;
210 };
211 template <class TimeMap, class TimeT, class Tag>
212 time_stamper<TimeMap, TimeT, Tag>
213 stamp_times(TimeMap pa, TimeT& time_counter, Tag) {
214 return time_stamper<TimeMap, TimeT, Tag>(pa, time_counter);
215 }
216
217 //========================================================================
218 // property_writer
219
220 template <class PA, class OutputIterator, class Tag>
221 struct property_writer
222 : public base_visitor<property_writer<PA, OutputIterator, Tag> >
223 {
224 typedef Tag event_filter;
225
226 property_writer(PA pa, OutputIterator out) : m_pa(pa), m_out(out) { }
227
228 template <class T, class Graph>
229 void operator()(T x, Graph&) { *m_out++ = get(m_pa, x); }
230 PA m_pa;
231 OutputIterator m_out;
232 };
233 template <class PA, class OutputIterator, class Tag>
234 property_writer<PA, OutputIterator, Tag>
235 write_property(PA pa, OutputIterator out, Tag) {
236 return property_writer<PA, OutputIterator, Tag>(pa, out);
237 }
238
239 //========================================================================
240 // property_put
241
242 /**
243 * Functor which just sets a given value to a vertex or edge in a property map.
244 */
245
246 template <typename PropertyMap, typename EventTag>
247 struct property_put
248 {
249 typedef EventTag event_filter;
250
251 property_put (PropertyMap property_map,
252 typename property_traits <PropertyMap>::value_type value) :
253 property_map_ (property_map), value_ (value)
254 {}
255
256 template <typename VertexOrEdge, typename Graph>
257 void operator() (VertexOrEdge v, const Graph&)
258 {
259 put (property_map_, v, value_);
260 }
261
262 private:
263 PropertyMap property_map_;
264 typename property_traits <PropertyMap>::value_type value_;
265 };
266
267 /**
268 * Creates a property_put functor which just sets a given value to a vertex or edge.
269 *
270 * @param property_map Given writeable property map
271 * @param value Fixed value of the map
272 * @param tag Event Filter
273 * @return The functor.
274 */
275
276 template <typename PropertyMap, typename EventTag>
277 inline property_put <PropertyMap, EventTag>
278 put_property (PropertyMap property_map,
279 typename property_traits <PropertyMap>::value_type value,
280 EventTag)
281 {
282 return property_put <PropertyMap, EventTag> (property_map, value);
283 }
284
285#define BOOST_GRAPH_EVENT_STUB(Event,Kind) \
286 typedef ::boost::Event Event##_type; \
287 template<typename Visitor> \
288 Kind##_visitor<std::pair<detail::functor_to_visitor<Event##_type, \
289 Visitor>, Visitors> > \
290 do_##Event(Visitor visitor) \
291 { \
292 typedef std::pair<detail::functor_to_visitor<Event##_type, Visitor>, \
293 Visitors> visitor_list; \
294 typedef Kind##_visitor<visitor_list> result_type; \
295 return result_type(visitor_list(visitor, m_vis)); \
296 }
297
298} /* namespace boost */
299
300#endif
301

source code of boost/boost/graph/visitors.hpp