#![allow(dead_code, deprecated, unused_variables, unused_mut)]
fn sq(x: u32) -> Result<u32, u32> {
    Ok(x * x)
}
fn err(x: u32) -> Result<u32, u32> {
    Err(x)
}
fn main() {
    assert_eq!(Ok(2).or_else(sq).or_else(sq), Ok(2));
    assert_eq!(Ok(2).or_else(err).or_else(sq), Ok(2));
    assert_eq!(Err(3).or_else(sq).or_else(err), Ok(9));
    assert_eq!(Err(3).or_else(err).or_else(err), Err(3));
}