     Python exception. Otherwise, <code>this-&gt;def(init_spec)</code> is
        called.</li>

        <li>If <code>init_spec</code> is not supplied,
        <code>this-&gt;def(init&lt;&gt;())</code> is called.</li>
      </ul>
    </dd>

    <dt><b>Rationale:</b>Allowing the user to specify constructor arguments
    in the <code>class_&lt;&gt;</code> constructor helps her to avoid the
    common run-time errors which result from invoking wrapped member
    functions without having exposed an <code>__init_