I think you should be able to use it already with progressive mode (https://kotlinlang.org/docs/whatsnew13.html#progressive-mode) but I haven’t tried it myself

Alternatively, as a quick workaround, you can define an extension function or property

exhaustive

that, when called on the

when

result, will force exhaustiveness. Another way is what I use often, to have the

when

a result of an expression function — it very often makes sense anyway

the built-in exhaustive mode is already default in Kotlin 1.7

my preference for a workaround in earlier versions or in cases where the built-in exhaustiveness checker isn't enabled by default is a trailing

when {
    ...
}.let { /* exhaustive */ }

which has no extra impact