error[E0446]: private type `Bar` in public interface --> $DIR/E0446.rs:10:5 | LL | struct Bar; | ---------- `Bar` declared as private ... LL | type Alias1 = Bar; | ^^^^^^^^^^^ can't leak private type error[E0446]: private trait `PrivTr` in public interface --> $DIR/E0446.rs:11:5 | LL | trait PrivTr {} | ------------ `PrivTr` declared as private ... LL | type Alias2 = Box; | ^^^^^^^^^^^ can't leak private trait error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0446`.