#![allow(dead_code, deprecated, unused_variables, unused_mut)]
fn main() {
    let mut slice: &[_] = &['a', 'b', 'c', 'd'];
    assert_eq!(None, slice.split_off(5..));
    assert_eq!(None, slice.split_off(..5));
    assert_eq!(None, slice.split_off(..= 4));
    let expected: &[char] = &['a', 'b', 'c', 'd'];
    assert_eq!(Some(expected), slice.split_off(..4));
}