title: boost::asio::serial_port reading after reconnecting Device
body: <p>I have a problem with the boost::asio::serial_port class reading from a GPS device (USB-Serial). Connecting the device and reading from it works fine, but when I disconnect and reconnect the device, read_some doesn't read any bytes from the port.</p>
  
  <p>As boost doesn't seam to detect that the serial port is gone ( is_open() returns true ), I periodically cancel(), close() and open( GPS_PORT ) the device when I don't get data, resetting the port options on the way. But this doesn't help either, the input buffer stays empty.</p>
  
  <p>Am I missing something, or doing something wrong, or is this a bug in asio? Is there a standard way to detect that the port is gone?</p>