an class="identifier">isEmpty</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">{</span><span class="keyword">return</span> <span class="identifier">isEmpty</span><span class="special">;}</span>
    <span class="identifier">size_t</span> <span class="identifier">getPointIdx</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">{</span><span class="keyword">return</span> <span class="identifier">pointIndex_</span><span clas