x_</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
        <span class="special">}</span>
    <span class="special">}</span>

    <span class="keyword">void</span> <span class="identifier">decrement</span><span class="special">()</span>
    <span class="special">{</span>
        <span class="keyword">if</span><span class="special">(</span><span class="identifier">pointIndex_</span><span class="special">&gt;</span><span class="number">0</span><span class="spe