 concessions compared to boost.asio <code>async_write()</code> free function. All, without exception, can be implemented without controversy. It would be busy-work and was omitted simply because there was no need. If we wanted to make an "official-looking" boost.asio extension then there would be merit in no longer conceding those concessions.</p>
<dl class="tparams"><dt>Template Parameters</dt><dd>
  <table class="tparams">
    <tr><td class="paramname">Task_err</td><td>boost.asio handler with same signatu