error[E0621]: explicit lifetime required in the type of `s`
 --> tests/ui/short-lifetime.rs:9:48
  |
9 |     pub fn ref_cast<'a>(s: &String) -> &'a Self;
  |                            -------             ^ lifetime `'a` required
  |                            |
  |                            help: add explicit lifetime `'a` to the type of `s`: `&'a String`