3 // This test ensures that each pointer type `P<X>` is covariant in `X`.
8 fn a<'r>(x: Box<&'static str>) -> Box<&'r str> {
12 fn b<'r, 'w>(x: &'w &'static str) -> &'w &'r str {
16 fn c<'r>(x: Arc<&'static str>) -> Arc<&'r str> {
20 fn d<'r>(x: Rc<&'static str>) -> Rc<&'r str> {