Generic constraint based on KClass property to scope down an extension function

Question

I am writing a kotlin extension function that should only work for sealed classes. Can I define a Generic Constraint - or something similar that serves the same purpose - such that an extension function would only work on classes that are a sealed class?

In my specific example I have an extension function that gets the ordinal of class type within it's sealed class:

inline fun <reified T : Any> T.sealedClassOrdinal() = T::class.sealedClassOrdinal()

inline fun <reified T : Any> KClass<T>.sealedClassOrdinal() =
    java.superclass?.classes?.indexOfFirst { sub -> sub == this@sealedClassOrdinal.java } ?: -1

Right now the first extension function can be called on Any. I would like to scope it down to only extend classes that are of sealed type. The property isSealed on KClass<T> exposes that info, but I don't see how to tell the compiler. I want something like this (pseudo code):

inline fun <reified T where T::class.isSealed> T.sealedClassOrdinal() = T::class.sealedClassOrdinal()

and/or

inline fun <reified T : Any> KClass<T>.sealedClassOrdinal() where this.isSealed =

Or any other solution that would achieve such a behavior.