ceph/src/boost/libs/graph/doc/PropertyGraph.html

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   9 <Head>
  10 <Title>PropertyGraph</Title>
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  17
  18 <H2><A NAME="concept:PropertyGraph"></A>
  19 PropertyGraph
  20 </H2>
  21
  22 A PropertyGraph is a graph that has some property associated with each
  23 of the vertices or edges in the graph. As a given graph may have
  24 several properties associated with each vertex or edge, a tag is used
  25 to identify which property is being accessed.  The graph provides a
  26 function 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&lt;G, Property&gt;::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&lt;Map&gt;::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&lt;G, PropertyTag&gt;::type</pre>
  91 The type of the property map for the property specified by
  92 <TT>PropertyTag</TT>.  This type must be a model of <a
  93 href="../../property_map/doc/ReadWritePropertyMap.html">ReadWritePropertyMap</a>
  94 with 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&lt;G, PropertyTag&gt;::const_type</pre>
 100 The type of the const property map for the property specified by
 101 <TT>PropertyTag</TT>. This type must be a model of <a
 102 href="../../property_map/doc/ReadablePropertyMap.html">ReadablePropertyMap</a>
 103 with 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,&nbsp;g)</TT> </td>
 115 <td>
 116 Returns the property map for the property specified by the
 117 <tt>PropertyTag</tt> type. The object <tt>p</tt> is only used to
 118 carry the type.<br>
 119 Return type: <TT>boost::property_map&lt;G,&nbsp;PropertyTag&gt;::type</TT> if <TT>g</TT> is mutable and <br><TT>boost::property_map&lt;G,&nbsp;PropertyTag&gt;::const_type</TT> otherwise.
 120 </td>
 121 </TR>
 122
 123 <tr>
 124 <td> <TT>get(p,&nbsp;g,&nbsp;x)</TT> </td>
 125 <td>
 126 Returns the property value (specified by the <tt>PropertyTag</tt> type)
 127 associated with object <tt>x</tt> (a vertex or edge).
 128 The object <tt>p</tt> is only used to carry the type.
 129 This function is equivalent to:<br>
 130 <tt>get(get(p, g), x)</tt><br>
 131 Return type: <tt>boost::property_traits&lt;Map&gt;::value_type</tt>
 132 </td>
 133 </TR>
 134
 135 <tr>
 136 <td> <TT>put(p,&nbsp;g,&nbsp;x,&nbsp;v)</TT> </td>
 137 <td>
 138 Set the property (specified by the <tt>PropertyTag</tt> type)
 139 associated with object <tt>x</tt> (a vertex or edge) to
 140 the value <tt>v</tt>. The object <tt>p</tt> is only used to carry the type.
 141 This function is equivalent to:<br>
 142 <tt>
 143 pmap = get(p, g);<br>
 144 put(pmap, x, v)
 145 </tt><br>
 146 Return type: <TT>void</TT>
 147 </td>
 148 </TR>
 149
 150
 151 </TABLE>
 152
 153 <H3>Complexity</H3>
 154
 155 The <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&lt;vertex_distance_t,int,property&lt;vertex_in_degree_t,int&gt; &gt;</tt> and <tt>PropertyTag=vertex_distance_t</tt>.</li>
 163 <li><tt>adjacency_list</tt> with <tt>VertexPropertyTag=property&lt;vertex_distance_t,int,property&lt;vertex_in_degree_t,int&gt; &gt;</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 &lt;class Graph, class X, class PropertyTag&gt;
 171   struct PropertyGraphConcept
 172   {
 173     typedef typename property_map&lt;G, PropertyTag&gt;::type Map;
 174     typedef typename property_map&lt;G, PropertyTag&gt;::const_type const_Map;
 175     void constraints() {
 176       BOOST_CONCEPT_ASSERT(( GraphConcept&lt;G&gt; ));
 177       BOOST_CONCEPT_ASSERT(( ReadWritePropertyMapConcept&lt;Map, X&gt; ));
 178       BOOST_CONCEPT_ASSERT(( ReadablePropertyMapConcept&lt;const_Map, X&gt; ));
 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&amp; 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&lt;Map&gt;::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 &copy; 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
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