er">async_write_response</span><span class="special">(</span><span class="number">500</span><span class="special">,</span> <span class="identifier">string_ref</span><span class="special">(</span><span class="string">"OK"</span><span class="special">),</span> <span class="identifier">reply</span><span class="special">,</span> <span class="identifier">yield</span><span class="special">);</span>
</pre>
</li>
<li class="listitem">
            <code class="computeroutput"><span class="identifier">headers_</span>