std::ostream& operator<<(std::ostream& out, const OSD::io_queue& q) {
  switch(q) {
  case OSD::io_queue::prioritized:
    out << "prioritized";
    break;
  case OSD::io_queue::weightedpriority:
    out << "weightedpriority";
    break;
  case OSD::io_queue::mclock_opclass:
    out << "mclock_opclass";
    break;
  case OSD::io_queue::mclock_client:
    out << "mclock_client";
    break;
  }
  return out;
}
std::ostream& operator<<(std::ostream& out, const OSD::io_queue& q) {
  switch(q) {
  case OSD::io_queue::prioritized:
    out << "prioritized";
    break;
  case OSD::io_queue::weightedpriority:
    out << "weightedpriority";
    break;
  case OSD::io_queue::mclock_opclass:
    out << "mclock_opclass";
    break;
  case OSD::io_queue::mclock_client:
    out << "mclock_client";
    break;
  }
  return out;
}