#![allow(dead_code, deprecated, unused_variables, unused_mut)]
fn main() {
    let x = Some("string");
    let v: Vec<&str> = x.into_iter().collect();
    assert_eq!(v, ["string"]);
    let x = None;
    let v: Vec<&str> = x.into_iter().collect();
    assert!(v.is_empty());
}