error[E0308]: `match` arms have incompatible types --> $DIR/issue-17728.rs:108:14 | LL | / match to_parse { LL | | "w" | "west" => RoomDirection::West, LL | | "e" | "east" => RoomDirection::East, LL | | "n" | "north" => RoomDirection::North, ... | LL | | "down" => RoomDirection::Down, | | ------------------- this and all prior arms are found to be of type `RoomDirection` LL | | _ => None | | ^^^^ expected `RoomDirection`, found `Option<_>` LL | | } | |_____- `match` arms have incompatible types | = note: expected enum `RoomDirection` found enum `Option<_>` error: lifetime may not live long enough --> $DIR/issue-17728.rs:15:28 | LL | fn attemptTraverse(&self, room: &Room, directionStr: &str) -> Result<&Room, &str> { | - - let's call the lifetime of this reference `'1` | | | let's call the lifetime of this reference `'2` ... LL | Some(entry) => Ok(entry), | ^^^^^^^^^ method was supposed to return data with lifetime `'2` but it is returning data with lifetime `'1` | help: consider introducing a named lifetime parameter | LL | fn attemptTraverse<'a>(&self, room: &'a Room, directionStr: &str) -> Result<&'a Room, &'a str> { | ++++ ++ ++ ++ error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0308`.