#![allow(dead_code, deprecated, unused_variables, unused_mut)]
fn main() {
    let k = 21;
    let x: Result<_, &str> = Ok("foo");
    assert_eq!(x.map_or_else(| e | k * 2, | v | v.len()), 3);
    let x: Result<&str, _> = Err("bar");
    assert_eq!(x.map_or_else(| e | k * 2, | v | v.len()), 42);
}