</span>
            <span class="keyword">struct</span> <span class="identifier">tag</span><span class="special">&lt;</span><span class="identifier">QRing</span><span class="special">&gt;</span>
            <span class="special">{</span>
                <span class="keyword">typedef</span> <span class="identifier">ring_tag</span> <span class="identifier">type</span><span class="special">;</span>
            <span class="special">};</span>
        <span class="special">}</span>
    <span class="special">}</s