error[E0308]: mismatched types --> $DIR/issue-46112.rs:9:21 | LL | fn main() { test(Ok(())); } | ^^ expected enum `Option`, found `()` | = note: expected enum `Option<()>` found unit type `()` help: try wrapping the expression in `Some` | LL | fn main() { test(Ok(Some(()))); } | +++++ + error: aborting due to previous error For more information about this error, try `rustc --explain E0308`.