Planet
navi homePPSaboutscreenshotsdownloaddevelopmentforum

source: downloads/boost_1_34_1/libs/graph/doc/IteratorConstructibleGraph.html @ 47

Last change on this file since 47 was 29, checked in by landauf, 17 years ago

updated boost from 1_33_1 to 1_34_1
File size: 4.4 KB
Line 
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>IteratorConstructibleGraph</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><A NAME="concept:IteratorConstructibleGraph"></A>
19IteratorConstructibleGraph
20</H1>
21
22The IteratorConstructibleGraph concept describes the interface for
23graph types that can be constructed using a kind of edge iterator. The
24edge iterator can be any <a
25href="http://www.sgi.com/tech/stl/InputIterator.html">InputIterator</a>
26that dereferences to a pair of integers <i>(i,j)</i>, which represent
27an edge that should be in the graph. The two integers <i>i</i> and
28<i>j</i> represent vertices where <i>0 <= i < |V|</i> and <i>0 <= j <
29|V|</i>.  The edge iterator's value type should be
30<tt>std::pair&lt;T,T&gt;</tt> (or at least be a structure that has
31members <tt>first</tt> and <tt>second</tt>) and the value type
32<tt>T</tt> of the pair must be convertible to the
33<tt>vertices_size_type</tt> of the graph (an integer).
34
35There are two valid expressions required by this concept, both of
36which are constructors. The first creates a graph object from a
37first/last iterator range. The second constructor also takes a
38first/last iterator range and in addition requires the number of
39vertices and number of edges. For some graph and edge iterator types
40the second constructor can be more efficient than the first.
41
42<h3>Example</h3>
43
44The following exampe creates two graph objects from an array of edges
45(vertex pairs). The type <tt>Edge*</tt> satisfies the requirements for
46an <a
47href="http://www.sgi.com/tech/stl/InputIterator.html">InputIterator</a>
48and can therefore be used to construct a graph.
49
50<pre>
51  typedef ... IteratorConstructibleGraph;
52  typedef boost::graph_traits<IteratorConstructibleGraph> Traits;
53
54  typedef std::pair<Traits::vertices_size_type, 
55    Traits::vertices_size_type> Edge;
56  Edge edge_array[] =
57    { Edge(0,1), Edge(0,2), Edge(0,3), Edge(0,4), Edge(0,5),
58      Edge(1, 2), Edge(1,5), Edge(1,3),
59      Edge(2, 4), Edge(2,5),
60      Edge(3, 2),
61      Edge(4, 3), Edge(4,1),
62      Edge(5, 4) };
63  Edge* first = edge_array,
64    last = edge_array + sizeof(edge_array)/sizeof(Edge);
65
66  IteratorConstructibleGraph G1(first, last);
67  // do something with G1 ...
68 
69  Traits::vertices_size_type size_V = 6;
70  Traits::edges_size_type size_E = sizeof(edge_array)/sizeof(Edge);
71  IteratorConstructibleGraph G2(first, last, size_V, size_E);
72  // do something with G2 ...
73</pre>
74
75<h3>Refinement of</h3>
76
77<a href="Graph.html">Graph</a>
78
79<h3>Notation</h3>
80
81<Table>
82<tr>
83<td><tt>G</tt></td>
84<td>is a graph type that models IteratorConstructibleGraph.</td>
85<tr>
86
87<tr>
88<td><tt>g</tt></td>
89<td>is an object of type <tt>G</tt>.</td>
90</tr>
91
92<tr>
93<td><tt>first, last</tt></td>
94<td>are edge iterators (see above).</td>
95</tr>
96
97<tr>
98<td><tt>Tr</tt></td>
99<td>is an object of type <tt>graph_traits&lt;G&gt;</tt>.</td>
100</tr>
101
102<tr>
103<td><tt>n_vertices</tt></td>
104<td>is an object of type <tt>Tr::vertices_size_type</tt>.</td>
105</tr>
106
107<tr>
108<td><tt>n_edges</tt></td>
109<td>is an object of type <tt>Tr::edges_size_type</tt>.</td>
110</tr>
111
112</Table>
113
114
115<h3>Valid Expressions</h3>
116
117<Table border>
118
119<tr>
120<td>
121<pre>G g(first, last);</pre>
122Construct graph object <tt>g</tt> given an edge range <tt>[first,last)</tt>.
123</td>
124<tr>
125
126<tr>
127<td>
128<pre>G g(first, last, n_vertices, n_edges);</pre>
129Construct graph object <tt>g</tt> given an edge range
130<tt>[first,last)</tt>, the number of vertices, and the number of
131edges.  Sometimes this constructor is more efficient than the
132constructor lacking the graph size information.
133</td>
134</tr>
135
136</Table>
137
138
139<!--
140<H3>Concept Checking Class</H3>
141
142<PRE>
143</PRE>
144-->
145
146<br>
147<HR>
148<TABLE>
149<TR valign=top>
150<TD nowrap>Copyright &copy 2000-2001</TD><TD>
151<A HREF="../../../people/jeremy_siek.htm">Jeremy Siek</A>,
152Indiana University (<A
153HREF="mailto:jsiek@osl.iu.edu">jsiek@osl.iu.edu</A>)<br>
154<A HREF="../../../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>,
156Indiana University (<A
157HREF="mailto:lums@osl.iu.edu">lums@osl.iu.edu</A>)
158</TD></TR></TABLE>
159
160</BODY>
161</HTML> 
Note: See TracBrowser for help on using the repository browser.