inition</h4>

<p>Defined in the header matrix_proxy.hpp.</p>

<h4>Template parameters</h4>

<table border="1">
<tbody>
<tr>
<th>Parameter</th>
<th>Description</th>
<th>Default</th>
</tr>

<tr>
<td><code>M</code> </td>
<td>The type of matrix referenced.</td>
<td>&nbsp;</td>
</tr>
</tbody>
</table>

<h4>Model of</h4>

<p><a href="expression.htm#matrix_expression">Matrix Expression</a>
.</p>

<h4>Type requirements</h4>

<p>None, except for those imposed by the requirements of <a href=
"expression.htm#matrix_ex