src/test/ui/issues/issue-18919.stderr

   1 error[E0277]: the size for values of type `dyn for<'r> Fn(&'r isize) -> isize` cannot be known at compilation time
   2   --> $DIR/issue-18919.rs:3:15
   3    |
   4 LL | fn ho_func(f: Option<FuncType>) {
   5    |               ^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
   6 ...
   7 LL | enum Option<T> {
   8    |             - required by this bound in `Option`
   9    |
  10    = help: the trait `Sized` is not implemented for `dyn for<'r> Fn(&'r isize) -> isize`
  11 help: you could relax the implicit `Sized` bound on `T` if it were used through indirection like `&T` or `Box<T>`
  12   --> $DIR/issue-18919.rs:7:13
  13    |
  14 LL | enum Option<T> {
  15    |             ^ this could be changed to `T: ?Sized`...
  16 LL |     Some(T),
  17    |          - ...if indirection was used here: `Box<T>`
  18
  19 error: aborting due to previous error
  20
  21 For more information about this error, try `rustc --explain E0277`.