documentation seems to be empty about noson HOT 4 CLOSED

 SONOS::ZonePtr toZone; // the zone target (coordinator) at which you want to link others zones
 std::vector<SONOS::ZonePtr> zones; // list of zones to join to the coordinator
 if (toZone && toZone->GetCoordinator())
 {
   for (std::vector<SONOS::ZonePtr>::const_iterator it = zones.begin(); it != zones.end(); ++it)
   {
     if ((*it)->GetZoneName() == toZone->GetZoneName())
       continue;
     for (std::vector<SONOS::ZonePlayerPtr>::iterator itr = (*it)->begin(); itr != (*it)->end(); ++itr)
     {
       SONOS::Player player(*itr);
       player.JoinToGroup(toZone->GetCoordinator()->GetUUID());
     }
   }
   return true;
 }
 return false;

  SONOS::ZonePtr toZone; // the zone target (coordinator) at which you want to link the room
  SONOS::ZonePlayerPtr room; // the room to join
  if (toZone && toZone->GetCoordinator() && room && room->IsValid())
  {
    SONOS::Player player(room);
    return player.JoinToGroup(toZone->GetCoordinator()->GetUUID());
  }
  else
    return false;

  SONOS::ZonePlayerPtr room; // the room to unjoin
  if (room && room->IsValid())
  {
    SONOS::Player player(room);
    return player.BecomeStandalone();
  }
  else
    return false;