n class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">mp</span><span class="special">);</span>

        <span class="comment">// clear_queue is called whenever the function </span>
        <span class="comment">// multi_pass::clear_queue is called on this instance</span>
        <span class="comment">//</span>
        <span class="comment">//   mp:    is a reference to the whole multi_pass instance</span>
        <span class="keyword">template</span> <span class="special"