[ceph.git] / ceph / src / boost / libs / graph / doc / EventVisitor.html

<HTML>
<!--
     Copyright (c) Jeremy Siek, Lie-Quan Lee, and Andrew Lumsdaine 2000
    
     Distributed under the Boost Software License, Version 1.0.
     (See accompanying file LICENSE_1_0.txt or copy at
     http://www.boost.org/LICENSE_1_0.txt)
  -->
<Head>
<Title>Boost Graph Library: EventVisitor</Title>
<BODY BGCOLOR="#ffffff" LINK="#0000ee" TEXT="#000000" VLINK="#551a8b" 
        ALINK="#ff0000"> 
<IMG SRC="../../../boost.png" 
     ALT="C++ Boost" width="277" height="86"> 

<BR Clear>

<H1>EventVisitor Concept</H1>

This concept defines the interface for single-event visitors. An
EventVisitor has an apply member function (<tt>operator()</tt>) which
is invoked within the graph algorithm at the event-point specified by
the <tt>event_filter</tt> typedef within the
EventVisitor. EventVisitor's can be combined into an <a
href="./EventVisitorList.html">EventVistorList</a>.

<p>
The following is the list of event tags that can be invoked in BGL
algorithms. Each tag corresponds to a member function of the visitor
for an algorithm. For example, the <a
href="./BFSVisitor.html">BFSVisitor</a> of <a
href="./breadth_first_search.html"><tt>breadth_first_search()</tt></a>
has a <tt>cycle_edge()</tt> member function. The corresponding tag is
<tt>on_cycle_edge</tt>. The first argument is the event visitor's
<tt>operator()</tt> must be either an edge or vertex descriptor
depending on the event tag.

<pre>
namespace boost {
  struct on_initialize_vertex { };
  struct on_start_vertex { };
  struct on_discover_vertex { };
  struct on_examine_edge { };
  struct on_tree_edge { };
  struct on_cycle_edge { };
  struct on_finish_vertex { };
  struct on_forward_or_cross_edge { };
  struct on_back_edge { };
  struct on_edge_relaxed { };
  struct on_edge_not_relaxed { };
  struct on_edge_minimized { };
  struct on_edge_not_minimized { };
} // namespace boost
</pre>


<h3>Refinement of</h3>

<a href="../../utility/CopyConstructible.html">Copy Constructible</a>
(copying a visitor should be a lightweight operation).

<h3>Notation</h3>

<Table>
<TR>
<TD><tt>G</tt></TD>
<TD>A type that is a model of <a href="./Graph.html">Graph</a>.</TD>
</TR>

<TR>
<TD><tt>g</tt></TD>
<TD>An object of type <tt>G</tt>.</TD>
</TR>

<TR>
<TD><tt>V</tt></TD>
<TD>A type that is a model of EventVisitor.</TD>
</TR>

<TR>
<TD><tt>vis</tt></TD>
<TD>An object of type <tt>V</tt>.</TD>
</TR>

<TR>
<TD><tt>x</tt></TD>
<TD>An object of type
<tt>boost::graph_traits&lt;G&gt;::vertex_descriptor</tt>
or <tt>boost::graph_traits&lt;G&gt;::edge_descriptor</tt>.</TD>
</TR>

</table>

<h3>Associated Types</h3>

<Table border>

<TR>
<TD>Event Filter </TD>
<TD><TT>V::event_filter</TT></TD>
<TD>
A tag struct to specify on which event the visitor should be invoked.
</TD>
</TR>

</table>

<h3>Valid Expressions</h3>

<Table border>

<tr>
<th>Name</th><th>Expression</th><th>Return Type</th><th>Description</th>
</tr>

<tr>
<td>Apply Visitor</td>
<td><TT>vis(x, g)</TT></TD>
<TD><TT>void</TT></TD>
<TD>
Invokes the visitor operation on object <tt>x</tt>, which is
either a vertex or edge descriptor of the graph.
</TD>
</TR>


</table>


<h3>Models</h3>

<ul>
 <li><a
 href="./predecessor_recorder.html"><tt>predecessor_recorder</tt></a>
 <li><a href="./distance_recorder.html"><tt>distance_recorder</tt></a>
 <li><a href="./time_stamper.html"><tt>time_stamper</tt></a>
 <li><a href="./property_writer.html"><tt>property_writer</tt></a>
 <li><a href="./null_visitor.html"><tt>null_visitor</tt></a>
</ul>

<h3>See Also</h3>

<a href="./EventVisitorList.html">EventVisitorList</a>,
<a href="./visitor_concepts.html">Visitor concepts</a>

<br>
<HR>
<TABLE>
<TR valign=top>
<TD nowrap>Copyright &copy; 2000-2001</TD><TD>
<A HREF="http://www.boost.org/people/jeremy_siek.htm">Jeremy Siek</A>,
Indiana University (<A
HREF="mailto:jsiek@osl.iu.edu">jsiek@osl.iu.edu</A>)<br>
<A HREF="http://www.boost.org/people/liequan_lee.htm">Lie-Quan Lee</A>, Indiana University (<A HREF="mailto:llee@cs.indiana.edu">llee@cs.indiana.edu</A>)<br>
<A HREF="http://www.osl.iu.edu/~lums">Andrew Lumsdaine</A>,
Indiana University (<A
HREF="mailto:lums@osl.iu.edu">lums@osl.iu.edu</A>)
</TD></TR></TABLE>

</BODY>
</HTML>
Commit	Line	Data
7c673cae FG	1	<HTML>
	2	<!--
	3	Copyright (c) Jeremy Siek, Lie-Quan Lee, and Andrew Lumsdaine 2000
	4
	5	Distributed under the Boost Software License, Version 1.0.
	6	(See accompanying file LICENSE_1_0.txt or copy at
	7	http://www.boost.org/LICENSE_1_0.txt)
	8	-->
	9	<Head>
	10	<Title>Boost Graph Library: EventVisitor</Title>
	11	<BODY BGCOLOR="#ffffff" LINK="#0000ee" TEXT="#000000" VLINK="#551a8b"
	12	ALINK="#ff0000">
	13	<IMG SRC="../../../boost.png"
	14	ALT="C++ Boost" width="277" height="86">
	15
	16	<BR Clear>
	17
	18	<H1>EventVisitor Concept</H1>
	19
	20	This concept defines the interface for single-event visitors. An
	21	EventVisitor has an apply member function (<tt>operator()</tt>) which
	22	is invoked within the graph algorithm at the event-point specified by
	23	the <tt>event_filter</tt> typedef within the
	24	EventVisitor. EventVisitor's can be combined into an <a
	25	href="./EventVisitorList.html">EventVistorList</a>.
	26
	27	<p>
	28	The following is the list of event tags that can be invoked in BGL
	29	algorithms. Each tag corresponds to a member function of the visitor
	30	for an algorithm. For example, the <a
	31	href="./BFSVisitor.html">BFSVisitor</a> of <a
	32	href="./breadth_first_search.html"><tt>breadth_first_search()</tt></a>
	33	has a <tt>cycle_edge()</tt> member function. The corresponding tag is
	34	<tt>on_cycle_edge</tt>. The first argument is the event visitor's
	35	<tt>operator()</tt> must be either an edge or vertex descriptor
	36	depending on the event tag.
	37
	38	<pre>
	39	namespace boost {
	40	struct on_initialize_vertex { };
	41	struct on_start_vertex { };
	42	struct on_discover_vertex { };
	43	struct on_examine_edge { };
	44	struct on_tree_edge { };
	45	struct on_cycle_edge { };
	46	struct on_finish_vertex { };
	47	struct on_forward_or_cross_edge { };
	48	struct on_back_edge { };
	49	struct on_edge_relaxed { };
	50	struct on_edge_not_relaxed { };
	51	struct on_edge_minimized { };
	52	struct on_edge_not_minimized { };
	53	} // namespace boost
	54	</pre>
	55
	56
	57	<h3>Refinement of</h3>
	58
	59	<a href="../../utility/CopyConstructible.html">Copy Constructible</a>
	60	(copying a visitor should be a lightweight operation).
	61
	62	<h3>Notation</h3>
	63
	64	<Table>
65	<TR>
66	<TD><tt>G</tt></TD>
67	<TD>A type that is a model of <a href="./Graph.html">Graph</a>.</TD>
68	</TR>
69
70	<TR>
71	<TD><tt>g</tt></TD>
72	<TD>An object of type <tt>G</tt>.</TD>
73	</TR>
74
75	<TR>
76	<TD><tt>V</tt></TD>
77	<TD>A type that is a model of EventVisitor.</TD>
78	</TR>
79
80	<TR>
81	<TD><tt>vis</tt></TD>
82	<TD>An object of type <tt>V</tt>.</TD>
83	</TR>
84
85	<TR>
86	<TD><tt>x</tt></TD>
87	<TD>An object of type
88	<tt>boost::graph_traits<G>::vertex_descriptor</tt>
89	or <tt>boost::graph_traits<G>::edge_descriptor</tt>.</TD>
90	</TR>
91
92	</table>
93
94	<h3>Associated Types</h3>
95
96	<Table border>
97
98	<TR>
99	<TD>Event Filter </TD>
100	<TD><TT>V::event_filter</TT></TD>
101	<TD>
102	A tag struct to specify on which event the visitor should be invoked.
103	</TD>
104	</TR>
105
106	</table>
107
108	<h3>Valid Expressions</h3>
109
110	<Table border>
111
112	<tr>
113	<th>Name</th><th>Expression</th><th>Return Type</th><th>Description</th>
114	</tr>
115
116	<tr>
117	<td>Apply Visitor</td>
118	<td><TT>vis(x, g)</TT></TD>
119	<TD><TT>void</TT></TD>
120	<TD>
121	Invokes the visitor operation on object <tt>x</tt>, which is
122	either a vertex or edge descriptor of the graph.
123	</TD>
124	</TR>
125
126
127	</table>
128
129
130	<h3>Models</h3>
131
132	<ul>
133	<li><a
134	href="./predecessor_recorder.html"><tt>predecessor_recorder</tt></a>
135	<li><a href="./distance_recorder.html"><tt>distance_recorder</tt></a>
136	<li><a href="./time_stamper.html"><tt>time_stamper</tt></a>
137	<li><a href="./property_writer.html"><tt>property_writer</tt></a>
138	<li><a href="./null_visitor.html"><tt>null_visitor</tt></a>
139	</ul>
140
141	<h3>See Also</h3>
142
143	<a href="./EventVisitorList.html">EventVisitorList</a>,
144	<a href="./visitor_concepts.html">Visitor concepts</a>
145
146	<br>
147	<HR>
148	<TABLE>
149	<TR valign=top>
150	<TD nowrap>Copyright © 2000-2001</TD><TD>
151	<A HREF="http://www.boost.org/people/jeremy_siek.htm">Jeremy Siek</A>,
152	Indiana University (<A
153	HREF="mailto:jsiek@osl.iu.edu">jsiek@osl.iu.edu</A>)<br>
154	<A HREF="http://www.boost.org/people/liequan_lee.htm">Lie-Quan Lee</A>, Indiana University (<A HREF="mailto:llee@cs.indiana.edu">llee@cs.indiana.edu</A>)<br>
155	<A HREF="http://www.osl.iu.edu/~lums">Andrew Lumsdaine</A>,
156	Indiana University (<A
157	HREF="mailto:lums@osl.iu.edu">lums@osl.iu.edu</A>)
158	</TD></TR></TABLE>
159
160	</BODY>
161	</HTML>