><tt class="docutils literal">T&amp; at( size_type n );</tt></p>
</li>
<li><p class="first"><tt class="docutils literal">const T&amp; at( size_type n ) const;</tt></p>
<blockquote>
<ul class="simple">
<li>Requirements: <tt class="docutils literal">n &lt; size()</tt></li>
<li>Effects: Returns a reference to the <tt class="docutils literal">n</tt>'th element</li>
<li>Throws: <tt class="docutils literal">bad_index</tt> if <tt class="docutils literal">n &gt;=size()</tt></li>
</ul>
</blockquote>
</li>
</ul>
</di