Structs, Enums, and Matching

Pattern Matching

Destructuring and Guards

Patterns can destructure tuples and add if guards, so one match expresses several conditions.

Program

Play the program to classify a point with a match guard.

pattern_match.rs 
fn main() {
    let point = (2, -3);
    let label = match point {
        (0, 0) => "origin",
        (x, _) if x > 0 => "right",
        _ => "other",
    };
    println!("{label}");
}
destructuring `(x, _)` pulls the first tuple field into `x`.
match guard `if x > 0` adds a condition to an arm.
order Arms are tried top to bottom; the first fit wins.