error[E0700]: hidden type for `impl Swap + 'a` captures lifetime that does not appear in bounds
  --> $DIR/rpit-hide-lifetime-for-swap.rs:17:5
   |
LL | fn hide<'a, 'b: 'a, T: 'static>(x: Rc<RefCell<&'b T>>) -> impl Swap + 'a {
   |             --                                            -------------- opaque type defined here
   |             |
   |             hidden type `Rc<RefCell<&'b T>>` captures the lifetime `'b` as defined here
LL |     x
   |     ^
   |
help: to declare that `impl Swap + 'a` captures `'b`, you can add an explicit `'b` lifetime bound
   |
LL | fn hide<'a, 'b: 'a, T: 'static>(x: Rc<RefCell<&'b T>>) -> impl Swap + 'a + 'b {
   |                                                                          ++++

error: aborting due to previous error

For more information about this error, try `rustc --explain E0700`.