#![allow(dead_code, deprecated, unused_variables, unused_mut)]
#![feature(substr_range)]
fn main() {
    let arr: &[[u32; 2]] = &[[0, 1], [2, 3]];
    let flat_arr: &[u32] = arr.as_flattened();
    let ok_elm: &[u32; 2] = flat_arr[0..2].try_into().unwrap();
    let weird_elm: &[u32; 2] = flat_arr[1..3].try_into().unwrap();
    assert_eq!(ok_elm, & [0, 1]);
    assert_eq!(weird_elm, & [1, 2]);
    assert_eq!(arr.element_offset(ok_elm), Some(0));
    assert_eq!(arr.element_offset(weird_elm), None);
}