Euclidean algorithm

gcd.rs

/// Recursive
fn gcd<T>(a: T, b: T) -> T where T: std::ops::Rem<Output = T> + Eq + From<u8> + Copy {
    if b == T::from(0u8) {
        a
    } else {
        gcd(b, a % b)
    }
}

/// Iterated
fn gcd<T>(a: T, b: T) -> T where T: std::ops::Rem<Output = T> + Eq + From<u8> + Copy {
    let mut snd = a;
    let mut rem = b;
    while rem != T::from(0u8) {
        let r = snd % rem;
        snd = rem;
        rem = r;
    }
    rem
}