">size_type&#160;</td>
          <td class="paramname"><em>idx</em></td><td>)</td>
          <td></td>
        </tr>
      </table>
  </td>
  <td class="mlabels-right">
<span class="mlabels"><span class="mlabel">inline</span></span>  </td>
  </tr>
</table>
</div><div class="memdoc">

<p>Element access operator. </p>
<dl class="exception"><dt>Exceptions</dt><dd>
  <table class="exception">
    <tr><td class="paramname">std::out_of_range</td><td>if idx is greater or equal to size. </td></tr>
  </table>
  </dd