roperty(&quot;gpa&quot;,gpa_map);

  manipulate_freds_info(properties);

  std::cout &lt;&lt; &quot;Fred's age: &quot; &lt;&lt; get(age_map,fred) &lt;&lt; &quot;\n&quot;
            &lt;&lt; &quot;Fred's gpa: &quot; &lt;&lt; get(gpa_map,fred) &lt;&lt; &quot;\n&quot;;
}
</pre>
<p>The code first creates two property maps using <tt class="docutils literal"><span class="pre">std::map</span></tt> and the
<tt class="docutils literal"><span class="pre">associative_property_map</span></tt> adaptor.  After initializ