error[E0517]: attribute should be applied to a struct or union --> $DIR/thaw-validate-invalid-enum.rs:3:8 | LL | #[repr(packed)] | ^^^^^^ LL | #[repr(u32)] LL | / enum E { LL | | A, LL | | B, LL | | C, LL | | } | |_- not a struct or union error[E0740]: field must implement `Copy` or be wrapped in `ManuallyDrop<...>` to be used in a union --> $DIR/thaw-validate-invalid-enum.rs:14:9 | LL | e: E, | ^^^^ | = note: union fields must not have drop side-effects, which is currently enforced via either `Copy` or `ManuallyDrop<...>` help: wrap the field type in `ManuallyDrop<...>` | LL | e: std::mem::ManuallyDrop, | +++++++++++++++++++++++ + error: aborting due to 2 previous errors Some errors have detailed explanations: E0517, E0740. For more information about an error, try `rustc --explain E0517`.