Exhaustiveness

2026-08-23

You can use open ranges for numerical matching to reach exhaustiveness:

fn order_of_magnitude(n: u32) -> &'static str {
    match n {
        0..=9      => "single digit",
        10..=99    => "double digit",
        100..=999  => "triple digit",
        1000..     => "four digits or more",   // open upto u32::MAX
    }
}