ifier">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="identifier">source</span><span class="special">(</span> <span class="comment">// constructor enters coroutine-function</span>
    <span class="special">[&amp;](</span><span class="identifier">boost</span><span class="special">::</span><span class="id