#[test]
pub fn test_once() {
    let mut i = 0;
    for _ in 0..3 {
        if x::once!() { i+= 1; }
        if x::once!() { i+= 1; }
    }
    assert_eq!(i, 2);
}



#[test]
pub fn test_chain() {
    let a = 0x1337;
    let b = [None,None,Some(&a)];
    let c = [None,Some(&b), None];
    assert_eq!(0x1337, x::ptr_chain!(&c as *const _, 0x8, 0x10, 0x0));
}