</dt>
<dd><p>
                  If <code class="computeroutput"><span class="keyword">true</span></code>, the underlying
                  socket is put into non-blocking mode and direct system calls may
                  fail with <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">error</span><span class="special">::</span><span class="identifier">would_block</span></cod