3 ms·
> how that ties in with subtyping In Swift it does not. But in Kotlin, `String?` is not an enum (sum type), but instead means `String | null`, a union type.
by ackfoobar 2y ago
> how that ties in with subtyping
In Swift it does not. But in Kotlin, `String?` is not an enum (sum type), but instead means `String | null`, a union type.