thrown containing <code>Error_code E</code>.<ul>
<li><code>E == boost::asio::error::would_block</code> specifically indicates the non-fatal condition wherein <code>*peer_socket</code> cannot currently receive, until it reaches readable state again (i.e., bytes and possibly handle arrive from peer).</li>
<li>Other <code>E</code> values indicate the connection is (potentially gracefully) permanently incapable of transmission.<ul>
<li>In particular <code>E == boost::asio::error::eof</code> indicates the connec