struct Hub {
    rooms: Vec<String>,
}

impl Actor for Hub {
    type Context = Context<Self>;
}

impl Hub {
    pub fn new() -> Hub {
        Hub {
            rooms: vec![]
        }
    }

    fn get_unique_id(&self) -> String {
        String::from("unique_id")
    }
}


struct CreateRoom;
impl Message for CreateRoom {
    type Result = String;
}

impl Handler<CreateRoom> for Hub {
    type Result = String;

    fn handle(&mut self, msg: CreateRoom, ctx: &mut Context<Self>) -> Self::Result {
        let id = self.get_unique_id();
        self.rooms.push(id.clone());
        id
    }
}


//External wrapper
struct HubWrapper(Addr<Hub>);
impl HubWrapper {
    pub fn add(&self) -> String {
        let res = self.0.send(CreateRoom);

        //how can I exec the future and return here the ID of this new room?
    }
}