fjbelchi / codetest-boardingpass-rust Goto Github PK

Hey there! https://twitter.com/rustlang/status/675324631268593665

Okay, so here's the issue:

pub fn generate() -> Vec<Box<BoardingPass>> {
    let mut vector: Vec<Box<BoardingPass>> = Vec::new();
    let madrid = City::new("Madrid".to_string());
    let barna = City::new("Barna".to_string());

    let madrid_barna = BoardingPassTrain::new("1", &madrid, &barna);
    vector.push(Box::new(madrid_barna));

    let barna_madrid = BoardingPassTrain::new("2", &barna, &madrid);
    vector.push(Box::new(barna_madrid));

    vector
}

The problem is, because you define madrid and barna in this function, when it returns, they'll go away. But you want a reference to them, which will point to nothing if that happens! That's why the compiler complains.

One way to solve it is to do #2. This makes the references come in as arguments, so that way, they won't go away after the function is over. Since your main.rs is empty right now, though, I can't see if this is the 100% best way, but it's what I would try at first. The other way is to use Rc<T>....