ass="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="identifier">X</span> <span class="identifier">x</span><span class="special">;</span>
            <span class="keyword">for</span><span class="special">(</span><span class="keyword">int</span><span class="special">=</span><span class="number">0</span><span class="special">;;++</span><span class="identifier">i</spa