if I have a `sealed interface` within a `sealed interface` I can't have an exhaustive when with the ...

# android

[Francesc]

if I have a sealed interface within a sealed interface I can't have an exhaustive when with the outer sealed interface entries (see example in thread). What's the reason for this?

[Francesc]

sealed interface DeviceType {
    object Phone : DeviceType
    sealed interface Tablet : DeviceType {
        object Small : Tablet
        object Large : Tablet
    }
}

val deviceType: DeviceType = DeviceType.Phone

fun foo() {
    when (deviceType) {
        DeviceType.Phone -> println("Phone")
        DeviceType.Tablet -> println("Tablet") <-- does not compile
    }
}

[Ejimax]

Replace the code inside foo with the following:

when (deviceType) {
        DeviceType.Phone -> println("Phone")
        is DeviceType.Tablet -> println("Tablet")
    }

[Francesc]

thanks, I eventually figured it out, but I appreciate the reply