error[E0308]: mismatched types --> $DIR/issue-48838.rs:2:14 | LL | Square = |x| x, | ^^^^^ expected `isize`, found closure | = note: expected type `isize` found closure `[closure@$DIR/issue-48838.rs:2:14: 2:17]` error: aborting due to previous error For more information about this error, try `rustc --explain E0308`.