I have many `enum`s with the following prototype:

enum class SomeHeaders(val label: String)

(for headers of different tables). How can I write a type parameter (like

val a: ???WHAT???

) so that it will be clear that it's

enum

(so I can use

values()

, etc.) and it had the

label

parameter. The parameter has easty solution: interface, but what about the

enum

limitation?

something like this seems to work, with generics:

interface Labeled {
    val label: String
}

enum class LabeledEnum(override val label: String): Labeled {
    THE_ONE("the one")
}

data class LabeledClass(override val label: String): Labeled

fun <T> test(a: T) where T: Enum<T>, T: Labeled {
    println(a)
}

fun main() {
    test(LabeledEnum.THE_ONE)
    test(LabeledClass("not the one")) // this line does not compile
}

without generics it would need so called intersection types, usually written as

Enum<T> & Labeled

or similarly, sadly Kotlin does not have these, nor there are any plans for them so far

Tahnk, TIL there is a

where

keyword exactly for this 👍🏻