fn main() {
let values = vec![1, 2, 3, 4];
match IntoIterator::into_iter(values) {
    mut it => loop {
                let n;
                match it.next() {
                    Some(val) => n = val,
                    None => break,
                };
                println!("{}", n);
            }
};
// or:
let arr = vec![13, 14, 15];
let mut it: ::std::vec::IntoIter<i32> = IntoIterator::into_iter(arr);
loop {
    let n;
    match it.next() {
        Some(val) => n = val,
        None => break,
    };
    println!("{}", n);
}
// or:
let vx = vec![22, 23, 24];
let mut it = IntoIterator::into_iter(vx);
while let Some(v) = it.next() {
    println!("{}", v);
}
} //main