error[E0308]: mismatched types
  --> $DIR/liveness-issue-2163.rs:15:30
   |
LL |       a.iter().all(|_| -> bool {
   |  ______________________________^
LL | |         //~^ ERROR mismatched types
LL | |     });
   | |_____^ expected bool, found ()
   |
   = note: expected type `bool`
              found type `()`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0308`.