1 error[E0631]: type mismatch in function arguments
2 --> $DIR/issue-60283.rs:17:13
4 LL | pub fn foo<T, F>(_: T, _: F)
5 | --- required by a bound in this
7 LL | F: for<'a> FnMut(<T as Trait<'a>>::Item),
8 | ----------------------------- required by this bound in `foo`
13 | expected signature of `fn(<() as Trait<'a>>::Item) -> _`
14 | found signature of `fn(()) -> _`
16 error[E0277]: the size for values of type `<() as Trait<'_>>::Item` cannot be known at compilation time
17 --> $DIR/issue-60283.rs:17:13
20 | ^^^^ doesn't have a size known at compile-time
22 ::: $SRC_DIR/core/src/mem/mod.rs:LL:COL
24 LL | pub fn drop<T>(_x: T) {}
25 | - required by this bound in `std::mem::drop`
27 = help: the trait `Sized` is not implemented for `<() as Trait<'_>>::Item`
28 help: consider further restricting the associated type
30 LL | fn main() where <() as Trait<'_>>::Item: Sized {
31 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
33 error: aborting due to 2 previous errors
35 Some errors have detailed explanations: E0277, E0631.
36 For more information about an error, try `rustc --explain E0277`.