n>GenLinearHierarchy;
<a name="l00251"></a>00251     
<a name="l00252"></a>00252     <span class="keyword">template</span>
<a name="l00253"></a>00253     &lt;
<a name="l00254"></a>00254         <span class="keyword">class </span>T1,
<a name="l00255"></a>00255         <span class="keyword">class </span>T2,
<a name="l00256"></a>00256         <span class="keyword">template</span> &lt;<span class="keyword">class</span>, <span class="keyword">class</span>&gt; <span class="keyword">class </span>Unit,
<a name="l00