lt;typename T&gt;<br />
manhattan_area_type <b>area</b>(const T&amp; polygon)</font></td>
            <td>Returns the area of an object that models
polygon_45_with_holes including subtracting the area of its holes from
the area of the outer shell polygon.</td>
          </tr>
          <tr>
            <td width="586"><font face="Courier New">template
&lt;typename T&gt;<br />
direction_1d <b>winding</b>(const T&amp; polygon)</font></td>
            <td>Returns the winding direction of an object that models
