error[E0308]: mismatched types --> $DIR/issue-48838.rs:12:14 | LL | Square = |x| x, //~ ERROR mismatched types | ^^^^^ expected isize, found closure | = note: expected type `isize` found type `[closure@$DIR/issue-48838.rs:12:14: 12:19]` error: aborting due to previous error For more information about this error, try `rustc --explain E0308`.