Comment by japgolly

Apply #[non_exhaustive] to publicly-exposed enums seems like a crazy recommendation to me. So much of the power of enums is that when you add a new case the compiler will flag all pattern matches that you need to update, which is a good thing because you're forced to consider each case. Having a catch-all saves dev-time but it risks not appropriately handling new cases becoming a runtime issue instead of a compile time error.