Steamworks manual callbacks

struct Handler {
    Handler();
    ~Handler();

    STEAM_CALLBACK_MANUAL(Handler, onLobbyDataUpdate, LobbyDataUpdate_t, _lobbyDataUpdateCallback);
};

Handler::Handler() {
    _lobbyDataUpdateCallback.Register(this, &SteamRoom::onLobbyDataUpdate);
}

Handler::~Handler() {
    _lobbyDataUpdateCallback.Unregister();
}

void Handler::onLobbyDataUpdate(LobbyDataUpdate_t *pCallback)
{
    //On update
}