error[E0308]: mismatched types
  --> $DIR/closure-no-fn-2.rs:16:27
   |
LL |     let bar: fn() -> u8 = || { b };
   |                           ^^^^^^^^ expected fn pointer, found closure
   |
   = note: expected type `fn() -> u8`
              found type `[closure@$DIR/closure-no-fn-2.rs:16:27: 16:35 b:_]`

error: aborting due to previous error

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