l">::</span><span class="identifier">uint64_t</span> <span class="identifier">base_mask</span> <span class="special">=</span> <span class="number">0xff</span><span class="special">;</span>

<span class="keyword">struct</span> <span class="identifier">lessthan</span> <span class="special">{</span>
  <span class="keyword">inline</span> <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">()(</span><span class="keyword">const</span> <span class="identifier">DATA_TYPE</sp