// WITH_STDLIB import kotlinx.serialization.* import kotlinx.serialization.json.* @Serializable class SomeClass(val i: Int) fun box(): String { val targetString = """{"i":42}""" val serializer = SomeClass.Companion.serializer() val descriptor = serializer.descriptor if (descriptor.toString() != "SomeClass(i: kotlin.Int)") return "Incorrect SerialDescriptor.toString(): $descriptor" val instance = SomeClass(42) val string = Json.encodeToString(serializer, instance) if (string != targetString) return "Incorrect serialization result: expected $targetString, got $string" val instance2 = Json.decodeFromString(serializer, string) if (instance2.i != instance.i) return "Incorrect deserialization result: expected ${instance.i}, got ${instance2.i}" return "OK" }