de> returned will be 1+; or a truthy <code>Error_code</code> is returned either via the out-arg or via thrown <code>Runtime_error</code>, and in the former case 0 is returned. </td></tr>
    <tr><td class="paramname">err_code</td><td>See <code>flow::Error_code</code> docs for error reporting semantics. <a class="el" href="namespaceipc.html#aa3192e586cc45d3e7c22463bf2760f89" title="Short-hand for flow::Error_code which is very common.">Error_code</a> generated: <code>boost::asio::error::would_block</code> (s