error[E0700]: hidden type for `impl Trait` captures lifetime that does not appear in bounds
  --> $DIR/region-escape-via-bound.rs:26:29
   |
LL | fn foo(x: Cell<&'x u32>) -> impl Trait<'y>
   |                             ^^^^^^^^^^^^^^
   |
note: hidden type `std::cell::Cell<&'x u32>` captures the lifetime 'x as defined on the function body at 26:1
  --> $DIR/region-escape-via-bound.rs:26:1
   |
LL | / fn foo(x: Cell<&'x u32>) -> impl Trait<'y>
LL | |     //~^ ERROR hidden type for `impl Trait` captures lifetime that does not appear in bounds [E0700]
LL | | where 'x: 'y
LL | | {
LL | |     x
LL | | }
   | |_^

error: aborting due to previous error

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