mber of type <code class="computeroutput">Expr</code>. 
      </p>
<p>If the <code class="computeroutput">Domain</code> parameter is dependent, you can specify it as
        <code class="computeroutput">typename Domain</code>, as in
        <code class="computeroutput">BOOST_PROTO_BASIC_EXTENDS(Expr, Derived, typename Domain)</code>
      </p>
<p>
        <span class="bold"><strong>Example:</strong></span></p>
<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span>