entifier">list</span><span class="special">&lt;</span><span class="identifier">polygon</span><span class="special">&gt;</span> <span class="identifier">output</span><span class="special">;</span>
    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">difference</span><span class="special">(</span><span class="identifier">green</span><span class="special">,</span> <span class="identifier">blue</sp