error[E0308]: mismatched types --> $DIR/issue-11844.rs:4:9 | LL | match a { | - this expression has type `Option>` LL | Ok(a) => | ^^^^^ expected `Option>`, found `Result<_, _>` | = note: expected enum `Option>` found enum `Result<_, _>` error: aborting due to previous error For more information about this error, try `rustc --explain E0308`.