[Rust] Changing data in a vector with a mutable iterator.

fn main() {
    let mut vec = vec![1, 2, 3];

    for element in vec.iter_mut() {
        *element = (*element) * (*element);
    }

    assert_eq!(vec[0], 1);
    assert_eq!(vec[1], 4);
    assert_eq!(vec[2], 9);
}