#[test]
pub fn test_distance() {
    let _ = x::dur![ 5 days 4 hours 7 minutes 2 seconds 2 minutes ];

    let a = [0u8, 2, 3];
    let p1 = &a[0];
    let p2 = &a[2];
    assert_eq!(x::distance(p1, p2), 2);
    assert_eq!(x::distance(p2, p1), 2);
    assert_eq!(x::distance(p1, p1), 0);


    let a = b"Hello World\0".as_ptr();
    assert_eq!(Some(11), x::iterate(a).position(|&a| a == 0));

    let b = b"H\0e\0l\0l\0o\0 \0W\0o\0r\0l\0d\0\0\0".as_ptr() as *const u16;
    let bytes: Vec<u16> = x::iterate(b)
        .take_while(|&&c| c != 0)
        .cloned().collect();
    assert_eq!("Hello World", String::from_utf16_lossy(bytes.as_slice()));


    let hello_world: String = char::decode_utf16(
        x::iterate(b).cloned().take_while(|&c| c != 0))
        .filter_map(|_r| _r.ok()).collect();
    assert_eq!("Hello World", hello_world);
}