#![allow(dead_code, deprecated, unused_variables, unused_mut)]
fn main() {
    let a = [-1i32, 4, 0, 1];
    let mut iter = a
        .into_iter()
        .map(|x| 16i32.checked_div(x))
        .take_while(|x| x.is_some())
        .map(|x| x.unwrap());
    assert_eq!(iter.next(), Some(- 16));
    assert_eq!(iter.next(), Some(4));
    assert_eq!(iter.next(), None);
}