#![allow(dead_code, deprecated, unused_variables, unused_mut)]
#![feature(result_option_map_or_default)]
fn main() {
    let x: Option<&str> = Some("hi");
    let y: Option<&str> = None;
    assert_eq!(x.map_or_default(| x | x.len()), 2);
    assert_eq!(y.map_or_default(| y | y.len()), 0);
}