`when` should know when it's been exhaustive if it...

# language-proposals

[benleggiero]

when should know when it's been exhaustive if it's evaluating a `sealed class`'s KClass. For instance:

sealed class MySealedClass {
    class SubclassA: MySealedClass()
    class SubclassB(val date: Date): MySealedClass()
}

fun makeInstance(sealedClass: KClass<MySealedClass>): MySealedClass
    = when (sealedClass) {
        SubclassA::class -> SubclassA()
        SubclassB::class -> SubclassB(Date())
    }

Error: Kotlin: 'when' expression must be exhaustive, add necessary 'else' branch

[benleggiero]

https://youtrack.jetbrains.com/issue/KT-16516

[orangy]

Thanks!