Hi, am I doing something wrong with this or is thi...

# announcements

[z3ntu]

Hi, am I doing something wrong with this or is this a Kotlin bug?

abstract class TestClass(open val value: Any)
class TestClass2(override val value: UInt) : TestClass(value)

val instance = TestClass2(0x1234u)
println("value: ${instance.value}")

I'm getting this exception:

java.lang.ClassCastException: java.lang.Integer cannot be cast to kotlin.UInt
	at Scratch_1$TestClass2.getValue(scratch_1.kts:2)
	at Scratch_1.<init>(scratch_1.kts:5)

[willyrs]

I think you should use generics for that:

abstract class TestClass<T : Any>(val value: T)
class TestClass2<UInt>(val value: UInt) : TestClass(value)

I don’t think you can override and change the type

[z3ntu]

It works for "normal" types (e.g. Int, Long), it just seems to have problems with the unsigned ones

[z3ntu]

And with your example slightly modified it still throws the same exception

abstract class TestClass<T: Any>(open val value: T)
class TestClass2(override val value: UInt) : TestClass<UInt>(value)

[z3ntu]

Hm actually like this it works:

abstract class TestClass<T: Any>(val value: T)
class TestClass2(value: UInt) : TestClass<UInt>(value)

[willyrs]

I didnt’ know it worked for normal types, but I would go with the generic solution, I feel it’s more typesafe and more “translatable” when using js or native

[Tobias Berger]

I'd guess this is a bug with the still experimental UInt type. But overriding a field-backed property of an abstract class with another field-backed property seems like a bad practice anyway.

[Ruckus]

I'd definitely report an issue