error[E0308]: `match` arms have incompatible types --> $DIR/issue-101465.rs:20:18 | LL | / match true { LL | | true => B, | | - this is found to be of type `B` LL | | false => C, | | ^ expected `B`, found `C` LL | | LL | | } | |_____- `match` arms have incompatible types | help: you could change the return type to be a boxed trait object | LL | fn foo() -> Box { | ~~~~~~~ + help: if you change the return type to expect trait objects, box the returned expressions | LL ~ true => Box::new(B), LL ~ false => Box::new(C), | error: aborting due to previous error For more information about this error, try `rustc --explain E0308`.