error[E0308]: mismatched types
  --> $DIR/liveness-issue-2163.rs:5:30
   |
LL |       a.iter().all(|_| -> bool {
   |  ______________________________^
LL | |
LL | |     });
   | |_____^ expected `bool`, found `()`

error: aborting due to previous error

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