#![allow(dead_code, deprecated, unused_variables, unused_mut)]
fn main() {
    let s = [
        (0, 0),
        (2, 1),
        (4, 1),
        (5, 1),
        (3, 1),
        (1, 2),
        (2, 3),
        (4, 5),
        (5, 8),
        (3, 13),
        (1, 21),
        (2, 34),
        (4, 55),
    ];
    assert_eq!(s.binary_search_by_key(& 13, |& (a, b) | b), Ok(9));
    assert_eq!(s.binary_search_by_key(& 4, |& (a, b) | b), Err(7));
    assert_eq!(s.binary_search_by_key(& 100, |& (a, b) | b), Err(13));
    let r = s.binary_search_by_key(&1, |&(a, b)| b);
    assert!(match r { Ok(1..= 4) => true, _ => false, });
}