n class="identifier">coroutines</span><span class="special">::</span><span class="identifier">asymmetric_coroutine</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;::</span><span class="identifier">pull_type</span><span class="special">&amp;</span> <span class="identifier">source</span><span class="special">){</span>
        <span class="keyword">while</span><span class="special">(</span><span class="identifier">source</span><span class="special">){</span>
   