error[E0308]: mismatched types --> $DIR/issue-50600.rs:2:13 | LL | fn([u8; |x: u8| {}]), | ^^^^^^^^^^ expected `usize`, found closure | = note: expected type `usize` found closure `{closure@$DIR/issue-50600.rs:2:13: 2:20}` error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0308`.