// Option type

fn safe_divide(dividend: i64, divisor: i64) -> Option<i64> {
    if 0 == divisor {
        None
    } else {
        Some(dividend / divisor)
    }
}

fn main() {

    let x = 10;
    let y = 5;

    match safe_divide(x, y) {
        Some(quotient) => println!("{} / {} = {}", x, y, quotient),
        None           => panic!("the disco!"),
    }

    let y = 0;

    match safe_divide(x, y) {
        Some(quotient) => println!("{} / {} = {}", x, y, quotient),
        _otherwise     => panic!("the disco!"),
    }

}