put">extent_gen</code> and
<code class="computeroutput">gen_type&lt;0&gt;::type</code> are the same.</p></dd>
<dt><span class="term"><code class="function">gen_type&lt;NumRanges+1&gt;::type  
operator[](const extent_range&amp; a_range) const;</code></span></dt>
<dd><p>This function returns a new object containing all previous
<code class="computeroutput">extent_range</code> objects in addition to
<code class="literal">a_range.</code> <code class="computeroutput">extent_range</code>
objects are aggregated by