otocol</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Executor</span><span class="special">&gt;</span>
<span class="keyword">void</span> <span class="identifier">do_async_echo</span> <span class="special">(</span><span class="identifier">basic_stream</span><span class="special">&lt;</span><span class="identifier">Protocol</span><span class="special">,</span> <span class="identifier">Executor</span><span class="special">&gt;&amp;</span> <span class="identifie