s content, so that the new content of is
            equivalent in both type and value to
            <code class="computeroutput">rhs</code> before forward.</td>
</tr>
<tr>
<td><p><span class="term">Throws:</span></p></td>
<td>
<code class="computeroutput">std::bad_alloc</code>
            or any exceptions arising from the move or copy constructor of the
            contained type. Assignment satisfies the strong guarantee
            of exception safety.</td>
</tr>
</tbody>
</table></div>
</li>
<li class