Irrefutable patterns

Another form of pattern matching is irrefutable patterns. A pattern is irrefutable when there's only one way to match it and it always succeeds. For instance, another way to get the elements of a tuple is with an irrefutable pattern:

let tuple = (24, 42);
let (a, b) = tuple;
println!("{}, {}", a, b);

In the second line, we assign the first element of the tuple to a and the second to b.