as shown here:
      </p>
<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">class</span> <span class="identifier">Handler</span> <span class="special">&gt;</span>
<span class="keyword">void</span> <span class="identifier">do_rpc</span><span class="special">(</span> <span class="identifier">string_view</span> <span class="identifier">s</span><span class="special">,</span> <span class="identifier">Handler</span><span class="special">&amp;&