1error[E0277]: expected a `FnOnce<()>` closure, found `{integer}` 2 --> $DIR/closure-expected.rs:3:23 3 | 4LL | let y = x.or_else(4); 5 | ------- ^ expected an `FnOnce<()>` closure, found `{integer}` 6 | | 7 | required by a bound introduced by this call 8 | 9 = help: the trait `FnOnce<()>` is not implemented for `{integer}` 10 = note: wrap the `{integer}` in a closure with no arguments: `|| { /* code */ }` 11note: required by a bound in `Option::<T>::or_else` 12 --> $SRC_DIR/core/src/option.rs:LL:COL 13 | 14LL | pub fn or_else<F: FnOnce() -> Option<T>>(self, f: F) -> Option<T> { 15 | ^^^^^^^^^^^^^^^^^^^^^ required by this bound in `Option::<T>::or_else` 16 17error: aborting due to previous error 18 19For more information about this error, try `rustc --explain E0277`. 20