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| <Head> |
| <Title>PropertyGraph</Title> |
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| |
| <BR Clear> |
| |
| <H2><A NAME="concept:PropertyGraph"></A> |
| PropertyGraph |
| </H2> |
| |
| A PropertyGraph is a graph that has some property associated with each |
| of the vertices or edges in the graph. As a given graph may have |
| several properties associated with each vertex or edge, a tag is used |
| to identify which property is being accessed. The graph provides a |
| function which returns a property map object. |
| |
| <P> |
| |
| <H3>Refinement of</H3> |
| |
| <a href="./Graph.html">Graph</a> |
| |
| <h3>Notation</h3> |
| |
| <Table> |
| <TR> |
| <TD><tt>G</tt></TD> |
| <TD>A type that is a model of PropertyGraph.</TD> |
| </TR> |
| |
| <TR> |
| <TD><tt>g</tt></TD> |
| <TD>An object of type <tt>G</tt>.</TD> |
| </TR> |
| |
| <TR> |
| <TD><tt>X</tt></TD> |
| <TD>Either the vertex or edge descriptor type for <tt>G</tt>.</TD> |
| </TR> |
| |
| <TR> |
| <TD><tt>x</tt></TD> |
| <TD>An object of type <tt>X</tt>.</TD> |
| </TR> |
| |
| |
| <TR> |
| <TD><tt>Map</tt></TD> |
| <TD>The type <tt>boost::property_map<G, Property>::const_type</tt>.</TD> |
| </TR> |
| |
| <TR> |
| <TD><tt>v</tt></TD> |
| <TD>An object of type <tt>boost::property_traits<Map>::value_type</tt>.</TD> |
| </TR> |
| |
| <TR> |
| <TD><tt>PropertyTag</tt></TD> |
| <TD>A type that models the <a href="./PropertyTag.html">PropertyTag</a> concept.</TD> |
| </TR> |
| |
| <TR> |
| <TD><tt>p</tt></TD> |
| <TD>An object of type <tt>PropertyTag</tt>.</td> |
| </TR> |
| |
| <TR> |
| <TD><tt>pmap</tt></TD> |
| <TD>An object of type <tt>Map</tt>.</td> |
| </TR> |
| |
| </table> |
| |
| <H3>Associated types</H3> |
| |
| <table border> |
| |
| <tr> |
| <td><pre>boost::property_map<G, PropertyTag>::type</pre> |
| The type of the property map for the property specified by |
| <TT>PropertyTag</TT>. This type must be a model of <a |
| href="../../property_map/doc/ReadWritePropertyMap.html">ReadWritePropertyMap</a> |
| with a key type the same as the graph's vertex or edge descriptor type. |
| </td> |
| </tr> |
| |
| <tr> |
| <td><pre>boost::property_map<G, PropertyTag>::const_type</pre> |
| The type of the const property map for the property specified by |
| <TT>PropertyTag</TT>. This type must be a model of <a |
| href="../../property_map/doc/ReadablePropertyMap.html">ReadablePropertyMap</a> |
| with a key type the same as the graph's vertex or edge descriptor type. |
| </td> |
| </tr> |
| |
| </table> |
| |
| <h3>Valid Expressions</h3> |
| |
| <table border> |
| |
| <tr> |
| <td> <TT>get(p, g)</TT> </td> |
| <td> |
| Returns the property map for the property specified by the |
| <tt>PropertyTag</tt> type. The object <tt>p</tt> is only used to |
| carry the type.<br> |
| Return 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. |
| </td> |
| </TR> |
| |
| <tr> |
| <td> <TT>get(p, g, x)</TT> </td> |
| <td> |
| Returns the property value (specified by the <tt>PropertyTag</tt> type) |
| associated with object <tt>x</tt> (a vertex or edge). |
| The object <tt>p</tt> is only used to carry the type. |
| This function is equivalent to:<br> |
| <tt>get(get(p, g), x)</tt><br> |
| Return type: <tt>boost::property_traits<Map>::value_type</tt> |
| </td> |
| </TR> |
| |
| <tr> |
| <td> <TT>put(p, g, x, v)</TT> </td> |
| <td> |
| Set the property (specified by the <tt>PropertyTag</tt> type) |
| associated with object <tt>x</tt> (a vertex or edge) to |
| the value <tt>v</tt>. The object <tt>p</tt> is only used to carry the type. |
| This function is equivalent to:<br> |
| <tt> |
| pmap = get(p, g);<br> |
| put(pmap, x, v) |
| </tt><br> |
| Return type: <TT>void</TT> |
| </td> |
| </TR> |
| |
| |
| </TABLE> |
| |
| <H3>Complexity</H3> |
| |
| The <tt>get()</tt> property map function must be constant time. |
| |
| |
| <H3>Models</H3> |
| |
| |
| <UL> |
| <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> |
| <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> |
| </UL> |
| |
| |
| <H3>Concept Checking Class</H3> |
| |
| <PRE> |
| template <class Graph, class X, class PropertyTag> |
| struct PropertyGraphConcept |
| { |
| typedef typename property_map<G, PropertyTag>::type Map; |
| typedef typename property_map<G, PropertyTag>::const_type const_Map; |
| void constraints() { |
| function_requires< GraphConcept<G> >(); |
| function_requires< ReadWritePropertyMapConcept<Map, X> >(); |
| function_requires< ReadablePropertyMapConcept<const_Map, X> >(); |
| |
| Map pmap = get(PropertyTag(), g); |
| pval = get(PropertyTag(), g, x); |
| put(PropertyTag(), g, x, pval); |
| ignore_unused_variable_warning(pmap); |
| } |
| void const_constraints(const G& g) { |
| const_Map pmap = get(PropertyTag(), g); |
| pval = get(PropertyTag(), g, x); |
| ignore_unused_variable_warning(pmap); |
| } |
| G g; |
| X x; |
| typename property_traits<Map>::value_type pval; |
| }; |
| </PRE> |
| |
| |
| <h3>See Also</h3> |
| |
| <a href="./property_map.html"><tt>property_map</tt></a> |
| |
| <br> |
| <HR> |
| <TABLE> |
| <TR valign=top> |
| <TD nowrap>Copyright © 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>) |
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