struct Car {
    model: String
}

struct Customer<'a> {
    car: Option<&'a Car>
}

impl <'a> Customer<'a> {
    fn new() -> Customer<'a> {
        Customer {
            car: None
        }
    }

    fn buy_car(&mut self, c: &'a Car) {
        self.car = Some(c);
    }

    fn sell_car(&mut self) {
        self.car = None;
    }
    fn trade_with(&mut self, other: &mut Customer<'a>) {
        let tmp = other.car;

        other.car = self.car;
        self.car = tmp;
    }
}
fn main() {
    let mut fabia = &Car{ model: "Skoda Fabia".to_string() };
    let logan = Car{ model: "Renault Logan".to_string() };

    let mut bob = Customer::new();
    let mut alice = Customer::new();
    let mut artem = Customer::new();

    bob.buy_car(&mut fabia);
    alice.buy_car(&logan);
    artem.buy_car(&fabia);


  //  bob.trade_with(&mut alice);

    //println!("{}", tempcar.model);
 //   println!("{}", alice.car);
}