public class RecordPatternsPreview1ExhaustivenessOK1 { static Pair<A> p1 = new Pair<>(new A(), new B()); static Pair<I> p2 = new Pair<>(new C(), new D()); public static void main(String[] args) { exhaustiveSwitch(); } static void exhaustiveSwitch() { switch (p2) { case Pair<I>(I i, C c) -> System.out.println("x"); case Pair<I>(I i, D d) -> System.out.println("y"); // Redundant default clause no longer necessary after fix of https://github.com/eclipse-jdt/eclipse.jdt.core/issues/455. // Old version with default clause see features1919/java19/RecordPatternsPreview1ExhaustivenessOK1.java. // default -> System.out.println("z"); } switch (p2) { case Pair<I>(C c, I i) -> System.out.println("a"); case Pair<I>(D d, C c) -> System.out.println("b"); case Pair<I>(D d1, D d2) -> System.out.println("c"); // Redundant default clause no longer necessary after fix of https://github.com/eclipse-jdt/eclipse.jdt.core/issues/455. // Old version with default clause see features1919/java19/RecordPatternsPreview1ExhaustivenessOK1.java. // default -> System.out.println("d"); } } } class A { } class B extends A { } sealed interface I permits C, D { } final class C implements I { } final class D implements I { } record Pair<T>(T x, T y) { }