typedef</span> Graph_data_t G;</div><div class="line"><a name="l00038"></a><span class="lineno">   38</span>&#160;</div><div class="line"><a name="l00039"></a><span class="lineno">   39</span>&#160;    <span class="keyword">public</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> <span class="keyword">typename</span> std::conditional&lt;is_