//> using scala 3.7.2 import language.experimental.modularity case class Event(tracked val payload: Payload) enum Payload { case Created() } val e = Event(Payload.Created()) def handleCreated(e: Event { def payload : Payload.Created}) = println(e.payload) @main def run = e match { case Event(payload: Payload.Created) => handleCreated(e.copy(payload = payload)) }

Exception in thread "main" java.lang.ClassCastException: class Payload$Created cannot be cast to class scala.Function0 (Payload$Created and scala.Function0 are in unnamed module of loader 'app') at demo$package$.handleCreated(demo.scala:12) at demo$package$.run(demo.scala:15) at run.main(demo.scala:14)