Pattern matching in function arguments

[aeveris]

In this stream you tried to use pattern matching in function arguments and were really close to figuring out the correct syntax.
So not to leave you with the impression that it can't be done, here's how you'd use pattern matching to destructure a tuple and print its individual values:

fn main() {
    let tup = (42, 24);
    print_tuple(tup);
}

fn print_tuple((x, y): (u32, u32)) {
    println!("x: {} | y: {}", x, y);
}

You use basically exactly the same syntax as if you were to destructure the tuple using a let statement, e.g. let (x, y) = tup; except that the type annotation is mandatory.
Destructuring of more complex values like structs or enums is also possible as shown in the following example:

struct Coords {
    x: i32,
    y: i32,
    z: i32,
}

fn main() {
    let coords = Coords { x: 2, y: 4, z: 8 };
    print_coords(coords);
}

fn print_coords(Coords{ x, y, z }: Coords) {
    println!("x: {} | y: {} | z: {}", x, y, z);
}

Like with let you can only destructure irrefutable patterns, i.e. patterns that will always match the provided values.