d">const</span> <span class="identifier">object_pool</span> <span class="special">&amp;);</span>
    <span class="keyword">void</span> <span class="keyword">operator</span><span class="special">=(</span><span class="keyword">const</span> <span class="identifier">object_pool</span> <span class="special">&amp;);</span>

  <span class="keyword">public</span><span class="special">:</span>
    <span class="keyword">typedef</span> <span class="identifier">ElementType</span> <span class="identifier">element_type</