0;    {</div><div class="line"><a name="l00039"></a><span class="lineno">   39</span>&#160;        <span class="comment">// -- Implementation detail --</span></div><div class="line"><a name="l00040"></a><span class="lineno">   40</span>&#160;</div><div class="line"><a name="l00041"></a><span class="lineno">   41</span>&#160;        <span class="keyword">typedef</span> T value_type;</div><div class="line"><a name="l00042"></a><span class="lineno">   42</span>&#160;        <span class="keyword">typedef</span>