an><span class="special">::</span><span class="identifier">polygon</span><span class="special">::</span><span class="identifier">polygon_data</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;</span> <span class="identifier">polygon</span><span class="special">;</span>
    <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">polygon</span><span class="special">::</span><span class="ide