> <span class="identifier">mode</span><span class="special">,</span>
    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">system</span><span class="special">::</span><span class="identifier">error_code</span> <span class="special">&amp;</span> <span class="identifier">ec</span><span class="special">);</span>
</pre>
<p>
            This function is used to modify the non-blocking mode of the underlying
            native socket. It has no effect on the behaviour of