n class="identifier">geometry</span><span class="special">::</span><span class="identifier">closure</span><span class="special">&lt;</span><span class="identifier">polygon_type</span><span class="special">&gt;::</span><span class="identifier">value</span><span class="special">;</span>

    <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"closure: "</span> <span class="special">&lt;&lt;</span> <s