Solution: Generic Response
sealed class Response<out R, out E>
class Success<out R>(val value: R) : Response<R, Nothing>()
class Failure<out E>(val error: E) : Response<Nothing, E>()
Example solution in playground
sealed class Response<out R, out E>
class Success<out R>(val value: R) : Response<R, Nothing>()
class Failure<out E>(val error: E) : Response<Nothing, E>()
fun usage() {
val rs1 = Success(1)
val rs2 = Success("ABC")
val re1 = Failure(Error())
val re2 = Failure("Error")
val rs3: Success<Number> = rs1
val rs4: Success<Any> = rs1
val re3: Failure<Throwable> = re1
val re4: Failure<Any> = re1
val r1: Response<Int, Throwable> = rs1
val r2: Response<Int, Throwable> = re1
}
