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<Head>
<Title>Iterator Property Map Adaptor</Title>
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<H2><A NAME="sec:iterator-property-map"></A>
</h2>
<PRE>
iterator_property_map<<a href="http://www.sgi.com/tech/stl/RandomAccessIterator.html">RandomAccessIterator</a>, OffsetMap, T, R>
</PRE>
<P>
This property map is an adaptor that converts any random access
iterator into a <a
href="./LvaluePropertyMap.html">Lvalue Property Map</a>.
The <tt>OffsetMap</tt> type is responsible for converting
key objects to integers that can be used as offsets with the
random access iterator.
<P>
<h3>Example</h3>
<pre>
// print out the capacity and flow for all the edges in the graph
template <class Graph, class CapacityPMap, class FlowPMap>
void print_network(Graph& G, CapacityPMap capacity, FlowPMap flow)
{
typedef typename boost::graph_traits<Graph>::vertex_iterator Viter;
typedef typename boost::graph_traits<Graph>::out_edge_iterator OutEdgeIter;
typedef typename boost::graph_traits<Graph>::in_edge_iterator InEdgeIter;
Viter ui, uiend;
for (boost::tie(ui, uiend) = vertices(G); ui != uiend; ++ui) {
OutEdgeIter out, out_end;
std::cout << *ui << "\t";
for(boost::tie(out, out_end) = out_edges(*ui, G); out != out_end; ++out)
std::cout << "--(" << get(capacity, *out) << ", "
<< get(flow, *out) << ")--> " << target(*out,G) << "\t";
std::cout << std::endl << "\t";
InEdgeIter in, in_end;
for(boost::tie(in, in_end) = in_edges(*ui, G); in != in_end; ++in)
std::cout << "<--(" << get(capacity, *in) << "," << get(flow, *in) << ")-- "
<< source(*in,G) << "\t";
std::cout << std::endl;
}
}
int main(int, char*[])
{
typedef boost::adjacency_list<boost::vecS, boost::vecS,
boost::bidirectionalS, boost::no_plugin,
boost::plugin<boost::id_tag, std::size_t> > Graph;
const int num_vertices = 9;
Graph G(num_vertices);
int capacity[] = { 10, 20, 20, 20, 40, 40, 20, 20, 20, 10 };
int flow[] = { 8, 12, 12, 12, 12, 12, 16, 16, 16, 8 };
// add edges to the graph, and assign each edge an ID number
// to index into the property arrays
add_edge(G, 0, 1, 0);
// ...
typedef boost::graph_traits<Graph>::edge_descriptor Edge;
typedef boost::property_map<Graph, boost::id_tag>::type EdgeID_PMap;
EdgeID_PMap edge_id = get(boost::edge_index(), G);
boost::iterator_property_map<int*, EdgeID_PMap, int, int&>
capacity_pa(capacity, edge_id),
flow_pa(flow, edge_id);
print_network(G, capacity_pa, flow_pa);
return 0;
}
</pre>
<H3>Where Defined</H3>
<P>
<a href="../../../boost/property_map/property_map.hpp"><TT>boost/property_map/property_map.hpp</TT></a>
<p>
<H3>Model Of</H3>
<a href="./LvaluePropertyMap.html">Lvalue Property Map</a>
<P>
<H3>Template Parameters</H3>
<P>
<TABLE border>
<TR>
<th>Parameter</th><th>Description</th><th>Default</th>
</tr>
<TR>
<TD><TT>Iterator</TT></TD>
<TD>Must be a model of <a href="http://www.sgi.com/tech/stl/RandomAccessIterator.html">Random Access Iterator</a>.</TD>
<TD> </td>
</tr>
<TR>
<TD><TT>OffsetMap</TT></TD> <TD>Must be a model of <a
href="./ReadablePropertyMap.html">Readable Property Map</a>
and the value type must be convertible to the difference type of the
iterator.</TD> <TD> </TD>
</TR>
<TR>
<TD><TT>T</TT></TD>
<TD>The value type of the iterator.</TD>
<TD><TT>std::iterator_traits<RandomAccessIterator>::value_type</TT></TD>
</TR>
<TR>
<TD><TT>R</TT></TD>
<TD>The reference type of the iterator.</TD>
<TD><TT>std::iterator_traits<RandomAccessIterator>::reference</TT></TD>
</TR>
</TABLE>
<P>
<H3>Members</H3>
<P>
In addition to the methods and functions required by <a
href="./LvaluePropertyMap.html">Lvalue Property Map</a>, this
class has the following members.
<hr>
<pre>
property_traits<iterator_property_map>::value_type
</pre>
This is the same type as
<TT>std::iterator_traits<Iterator>::value_type</TT>.
<hr>
<pre>
iterator_property_map(Iterator i)
</pre>
Constructor. The OffsetMap is default constructed.
<hr>
<pre>
iterator_property_map(Iterator i, OffsetMap m)
</pre>
Constructor.
<hr>
<pre>
reference operator[](difference_type v) const
</pre>
The operator bracket for property access. The <TT>reference</TT> and
<TT>difference_type</TT> types are from
<TT>std::iterator_traits<Iterator></TT>.
<hr>
<h3>Non-Member functions</h3>
<hr>
<pre>
template <class RAIter, class OffsetMap>
iterator_property_map<RAIter, OffsetMap,
typename std::iterator_traits<RAIter>::value_type,
typename std::iterator_traits<RAIter>::reference
>
make_iterator_property_map(RAIter iter, OffsetMap omap)
</pre>
A function for conveniently creating an iterator map.
<hr>
<pre>
template <class RAIter, class OffsetMap, class ValueType>
iterator_property_map<RAIter, OffsetMap,
typename std::iterator_traits<RAIter>::value_type,
typename std::iterator_traits<RAIter>::reference
>
make_iterator_property_map(RAIter iter, OffsetMap omap, ValueType dummy_arg)
</pre>
Use this function instead of the 2-argument version if
your compiler does not support partial specialization
(like Visual C++).
<hr>
<br>
<HR>
<TABLE>
<TR valign=top>
<TD nowrap>Copyright © 2000-2002</TD><TD>
<a HREF="http://www.boost.org/people/jeremy_siek.htm">Jeremy Siek</a>,
Univ.of Notre Dame (<A
HREF="mailto:jsiek@osl.iu.edu">jsiek@osl.iu.edu</A>)<br>
<A HREF="http://www.boost.org/people/liequan_lee.htm">Lie-Quan Lee</A>, Univ.of Notre Dame (<A HREF="mailto:llee1@osl.iu.edu">llee1@osl.iu.edu</A>)<br>
<A HREF="http://www.osl.iu.edu/~lums">Andrew Lumsdaine</A>,
Univ.of Notre Dame (<A
HREF="mailto:lums@osl.iu.edu">lums@osl.iu.edu</A>)
</TD></TR></TABLE>
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