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<Head>
<Title>Reference Property Map</Title>
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<H2><A NAME="sec:identity-property-map"></A>
</h2>
<PRE>
template &lt;typename KeyType, typename ValueType&gt;
class ref_property_map
</PRE>

This property map wraps a reference to some particular object, and
returns that reference whenever a key object is input.

<H3>Where Defined</H3>

<P>
<a href="../../../boost/property_map/property_map.hpp"><TT>boost/property_map/property_map.hpp</TT></a>

<h3>Model of</h3>

<a href="./LvaluePropertyMap.html">Lvalue Property Map</a>

<h3>Associated Types</h3>

<table border>
<tr>
<th>Type</th><th>Description</th>
</tr>

<tr>
<td><tt>
boost::property_traits&lt;ref_property_map&gt;::value_type
</tt></td>
<td>
This type is the <tt>ValueType</tt> with which the template instantiated.
</td>
</tr>

<tr>
<td><tt>
boost::property_traits&lt;ref_property_map&gt;::key_type
</tt></td>
<td>
This type is the <tt>KeyType</tt> with which the template instantiated.
</td>
</tr>

<tr>
<td><tt>
boost::property_traits&lt;ref_property_map&gt;::category
</tt></td>
<td>
This type is <tt>boost::lvalue_property_map_tag</tt>.
</td>
</tr>

</table>

<h3>Member Functions</h3>

<table border>
<tr>
<th>Member</th><th>Description</th>
</tr>


<tr>
<td><tt>
ref_property_map(ValueType&amp; v)
</tt></td>
<td>
The constructor for ref_property_map is provided the reference that
the property map will return when queried.
</td>
</tr>

<tr>
<td><tt>
ref_property_map(const ref_property_map&amp; x)
</tt></td>
<td>
Copy constructor.
</td>
</tr>

<tr>
<td><tt>
ValueType&amp; operator[](KeyType const&amp;) const
</tt></td>
<td>
Returns the contained reference.
</td>
</tr>

</table>


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