1<HTML> 2<!-- 3 Copyright (c) Jeremy Siek 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>PropertyGraph</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<H2><A NAME="concept:PropertyGraph"></A> 19PropertyGraph 20</H2> 21 22A PropertyGraph is a graph that has some property associated with each 23of the vertices or edges in the graph. As a given graph may have 24several properties associated with each vertex or edge, a tag is used 25to identify which property is being accessed. The graph provides a 26function which returns a property map object. 27 28<P> 29 30<H3>Refinement of</H3> 31 32<a href="./Graph.html">Graph</a> 33 34<h3>Notation</h3> 35 36<Table> 37<TR> 38<TD><tt>G</tt></TD> 39<TD>A type that is a model of PropertyGraph.</TD> 40</TR> 41 42<TR> 43<TD><tt>g</tt></TD> 44<TD>An object of type <tt>G</tt>.</TD> 45</TR> 46 47<TR> 48<TD><tt>X</tt></TD> 49<TD>Either the vertex or edge descriptor type for <tt>G</tt>.</TD> 50</TR> 51 52<TR> 53<TD><tt>x</tt></TD> 54<TD>An object of type <tt>X</tt>.</TD> 55</TR> 56 57 58<TR> 59<TD><tt>Map</tt></TD> 60<TD>The type <tt>boost::property_map<G, Property>::const_type</tt>.</TD> 61</TR> 62 63<TR> 64<TD><tt>v</tt></TD> 65<TD>An object of type <tt>boost::property_traits<Map>::value_type</tt>.</TD> 66</TR> 67 68<TR> 69<TD><tt>PropertyTag</tt></TD> 70<TD>A type that models the <a href="./PropertyTag.html">PropertyTag</a> concept.</TD> 71</TR> 72 73<TR> 74<TD><tt>p</tt></TD> 75<TD>An object of type <tt>PropertyTag</tt>.</td> 76</TR> 77 78<TR> 79<TD><tt>pmap</tt></TD> 80<TD>An object of type <tt>Map</tt>.</td> 81</TR> 82 83</table> 84 85<H3>Associated types</H3> 86 87<table border> 88 89<tr> 90<td><pre>boost::property_map<G, PropertyTag>::type</pre> 91The type of the property map for the property specified by 92<TT>PropertyTag</TT>. This type must be a model of <a 93href="../../property_map/doc/ReadWritePropertyMap.html">ReadWritePropertyMap</a> 94with a key type the same as the graph's vertex or edge descriptor type. 95</td> 96</tr> 97 98<tr> 99<td><pre>boost::property_map<G, PropertyTag>::const_type</pre> 100The type of the const property map for the property specified by 101<TT>PropertyTag</TT>. This type must be a model of <a 102href="../../property_map/doc/ReadablePropertyMap.html">ReadablePropertyMap</a> 103with a key type the same as the graph's vertex or edge descriptor type. 104</td> 105</tr> 106 107</table> 108 109<h3>Valid Expressions</h3> 110 111<table border> 112 113<tr> 114<td> <TT>get(p, g)</TT> </td> 115<td> 116Returns the property map for the property specified by the 117<tt>PropertyTag</tt> type. The object <tt>p</tt> is only used to 118carry the type.<br> 119Return type: <TT>boost::property_map<G, PropertyTag>::type</TT> if <TT>g</TT> is mutable and <br><TT>boost::property_map<G, PropertyTag>::const_type</TT> otherwise. 120</td> 121</TR> 122 123<tr> 124<td> <TT>get(p, g, x)</TT> </td> 125<td> 126Returns the property value (specified by the <tt>PropertyTag</tt> type) 127associated with object <tt>x</tt> (a vertex or edge). 128The object <tt>p</tt> is only used to carry the type. 129This function is equivalent to:<br> 130<tt>get(get(p, g), x)</tt><br> 131Return type: <tt>boost::property_traits<Map>::value_type</tt> 132</td> 133</TR> 134 135<tr> 136<td> <TT>put(p, g, x, v)</TT> </td> 137<td> 138Set the property (specified by the <tt>PropertyTag</tt> type) 139associated with object <tt>x</tt> (a vertex or edge) to 140the value <tt>v</tt>. The object <tt>p</tt> is only used to carry the type. 141This function is equivalent to:<br> 142<tt> 143pmap = get(p, g);<br> 144put(pmap, x, v) 145</tt><br> 146Return type: <TT>void</TT> 147</td> 148</TR> 149 150 151</TABLE> 152 153<H3>Complexity</H3> 154 155The <tt>get()</tt> property map function must be constant time. 156 157 158<H3>Models</H3> 159 160 161<UL> 162<LI><tt>adjacency_list</tt> with <tt>VertexProperty=property<vertex_distance_t,int,property<vertex_in_degree_t,int> ></tt> and <tt>PropertyTag=vertex_distance_t</tt>.</li> 163<li><tt>adjacency_list</tt> with <tt>VertexPropertyTag=property<vertex_distance_t,int,property<vertex_in_degree_t,int> ></TT> and <tt>PropertyTag=vertex_in_degree_t</tt>.</li> 164</UL> 165 166 167<H3>Concept Checking Class</H3> 168 169<PRE> 170 template <class Graph, class X, class PropertyTag> 171 struct PropertyGraphConcept 172 { 173 typedef typename property_map<G, PropertyTag>::type Map; 174 typedef typename property_map<G, PropertyTag>::const_type const_Map; 175 void constraints() { 176 BOOST_CONCEPT_ASSERT(( GraphConcept<G> )); 177 BOOST_CONCEPT_ASSERT(( ReadWritePropertyMapConcept<Map, X> )); 178 BOOST_CONCEPT_ASSERT(( ReadablePropertyMapConcept<const_Map, X> )); 179 180 Map pmap = get(PropertyTag(), g); 181 pval = get(PropertyTag(), g, x); 182 put(PropertyTag(), g, x, pval); 183 ignore_unused_variable_warning(pmap); 184 } 185 void const_constraints(const G& g) { 186 const_Map pmap = get(PropertyTag(), g); 187 pval = get(PropertyTag(), g, x); 188 ignore_unused_variable_warning(pmap); 189 } 190 G g; 191 X x; 192 typename property_traits<Map>::value_type pval; 193 }; 194</PRE> 195 196 197<h3>See Also</h3> 198 199<a href="./property_map.html"><tt>property_map</tt></a> 200 201<br> 202<HR> 203<TABLE> 204<TR valign=top> 205<TD nowrap>Copyright © 2000-2001</TD><TD> 206<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>) 207</TD></TR></TABLE> 208 209</BODY> 210</HTML> 211
