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

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<title>AddEdgeVisitor Concept</title>
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<h1>AddEdgeVisitor Concept</h1>

The AddEdgeVisitor concept exists to allow for some indirection in algorithms
that modify graphs by adding edges. In such algorithms, it may be convenient
to perform additional operations (such as updating an edge index map) at 
points in the algorithm where an edge addition occurs. Replacing calls to
to <tt>add_edge</tt> with calls to <tt>AddEdgeVisitor::visit_vertex_pair</tt>
allows for such operations to be defined independently from the algorithm.

<h3>Notation</h3>

<table>
<tbody>

<tr>
<td> <tt>Visitor</tt> </td>
<td> is a type that models the AddEdgeVisitor concept </td>
</tr>

<tr> 
<td> <tt>vis</tt> </td>  
<td> is an object of type Visitor </td>
</tr>

<tr>
<td> <tt>Graph</tt> </td>
<td> is the type of a graph </td>
</tr>

<tr> 
<td> <tt>u,v</tt> </td>  
<td> are objects of type <tt>graph_traits&lt;Graph&gt;::vertex_descriptor</tt>
</td>
</tr>

<tr> 
<td> <tt>e</tt> </td>  
<td> is an object of type <tt>graph_traits&lt;Graph&gt;::edge_descriptor</tt> 
</td>
</tr>

<tr>
<td> <tt>v</tt> </td>
<td> is an object of type <tt>graph_traits&lt;Graph&gt;::vertex_descriptor</tt>
</td>

</tr><tr>
<td> 

</td></tr></tbody></table>


<h3>Associated Types</h3>

None

<h3>Valid Expressions</h3>

<p>

<table border="1">

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

</tr><tr> 
<td> Add an Edge </td>
<td> <tt>vis.visit_vertex_pair(u, v, g)</tt>  </td>
<td> <tt>void</tt></td>
<td> Invoked every time an edge between vertices <tt>u</tt> and <tt>v</tt>
     should be added to the graph <tt>g</tt>.
</td></tr>

</tbody></table>

</p><h3>Models</h3>

Two models of this concept are defined in the file 
<a href="../../../boost/graph/planar_detail/add_edge_visitors.hpp">
<tt>add_edge_visitors.hpp</tt></a>:

<ul>
<li><tt>default_add_edge_visitor</tt>: The constructor of this class takes
no arguments.<tt>visit_vertex_pair(u, v, g)</tt> is just a dispatch to
<tt>add_edge(u, v, g)</tt>. 
<li><tt>edge_index_update_visitor</tt>: The constructor of this class takes
two arguments: the first, an EdgeIndexMap,
is a <a href="../../property_map/doc/ReadWritePropertyMap.html">
ReadWritePropertyMap</a> that maps each edge in the associated graph 
<tt>g</tt> to a distinct integer in the range <tt>[0, num_edges(g))</tt>. 
The second argument is the number of edges in the underlying graph, which 
serves as the "next available index" counter within the visitor.
For example, in the case the graph used has an initialized interior 
edge index, the <tt>edge_index_update_visitor</tt> constructor should be 
called with <tt>get(edge_index, g)</tt> as the edge index and 
<tt>num_edges(g)</tt> as the next available index. When 
<tt>visit_vertex_pair(u, v, g)</tt> is called, the 
<tt>edge_index_update_visitor</tt> will add the edge <i>(u,v)</i> to the graph
and update the edge index for the newly created edge.
</ul>

<p>

<br>
</p><hr>
Commit	Line	Data
7c673cae FG	1	<html>
	2	<head>
	3	<!-- Copyright 2007 Aaron Windsor
	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	-->
	10	<title>AddEdgeVisitor Concept</title>
	11	</head>
	12	<body alink="#ff0000"
	13	bgcolor="#ffffff"
	14	link="#0000ee"
	15	text="#000000"
	16	vlink="#551a8b">
	17
	18	<img src="../../../boost.png" alt="C++ Boost" height="86" width="277">
	19
	20	<br clear="">
	21
	22	<h1>AddEdgeVisitor Concept</h1>
	23
	24	The AddEdgeVisitor concept exists to allow for some indirection in algorithms
	25	that modify graphs by adding edges. In such algorithms, it may be convenient
	26	to perform additional operations (such as updating an edge index map) at
	27	points in the algorithm where an edge addition occurs. Replacing calls to
	28	to <tt>add_edge</tt> with calls to <tt>AddEdgeVisitor::visit_vertex_pair</tt>
	29	allows for such operations to be defined independently from the algorithm.
	30
	31	<h3>Notation</h3>
	32
	33	<table>
	34	<tbody>
	35
	36	<tr>
	37	<td> <tt>Visitor</tt> </td>
	38	<td> is a type that models the AddEdgeVisitor concept </td>
	39	</tr>
	40
	41	<tr>
	42	<td> <tt>vis</tt> </td>
	43	<td> is an object of type Visitor </td>
	44	</tr>
	45
	46	<tr>
	47	<td> <tt>Graph</tt> </td>
	48	<td> is the type of a graph </td>
	49	</tr>
	50
	51	<tr>
	52	<td> <tt>u,v</tt> </td>
	53	<td> are objects of type <tt>graph_traits<Graph>::vertex_descriptor</tt>
	54	</td>
	55	</tr>
	56
	57	<tr>
	58	<td> <tt>e</tt> </td>
	59	<td> is an object of type <tt>graph_traits<Graph>::edge_descriptor</tt>
	60	</td>
	61	</tr>
	62
	63	<tr>
	64	<td> <tt>v</tt> </td>
65	<td> is an object of type <tt>graph_traits<Graph>::vertex_descriptor</tt>
66	</td>
67
68	</tr><tr>
69	<td>
70
71	</td></tr></tbody></table>
72
73
74	<h3>Associated Types</h3>
75
76	None
77
78	<h3>Valid Expressions</h3>
79
80	<p>
81
82	<table border="1">
83
84	<tbody><tr><th>Name</th><th>Expression</th><th>Return Type</th>
85	<th>Description</th>
86
87	</tr><tr>
88	<td> Add an Edge </td>
89	<td> <tt>vis.visit_vertex_pair(u, v, g)</tt> </td>
90	<td> <tt>void</tt></td>
91	<td> Invoked every time an edge between vertices <tt>u</tt> and <tt>v</tt>
92	should be added to the graph <tt>g</tt>.
93	</td></tr>
94
95	</tbody></table>
96
97	</p><h3>Models</h3>
98
99	Two models of this concept are defined in the file
100	<a href="../../../boost/graph/planar_detail/add_edge_visitors.hpp">
101	<tt>add_edge_visitors.hpp</tt></a>:
102
103	<ul>
104	<li><tt>default_add_edge_visitor</tt>: The constructor of this class takes
105	no arguments.<tt>visit_vertex_pair(u, v, g)</tt> is just a dispatch to
106	<tt>add_edge(u, v, g)</tt>.
107	<li><tt>edge_index_update_visitor</tt>: The constructor of this class takes
108	two arguments: the first, an EdgeIndexMap,
109	is a <a href="../../property_map/doc/ReadWritePropertyMap.html">
110	ReadWritePropertyMap</a> that maps each edge in the associated graph
111	<tt>g</tt> to a distinct integer in the range <tt>[0, num_edges(g))</tt>.
112	The second argument is the number of edges in the underlying graph, which
113	serves as the "next available index" counter within the visitor.
114	For example, in the case the graph used has an initialized interior
115	edge index, the <tt>edge_index_update_visitor</tt> constructor should be
116	called with <tt>get(edge_index, g)</tt> as the edge index and
117	<tt>num_edges(g)</tt> as the next available index. When
118	<tt>visit_vertex_pair(u, v, g)</tt> is called, the
119	<tt>edge_index_update_visitor</tt> will add the edge <i>(u,v)</i> to the graph
120	and update the edge index for the newly created edge.
121	</ul>
122
123	<p>
124
125	<br>
126	</p><hr>
127