I have an abstract class with a subclass. I want the subclass to define a property with type Class, ...

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[Mark Buikema]

I have an abstract class with a subclass. I want the subclass to define a property with type Class, but its implementation should be a subclass of Param . How do I define this?

abstract class Params

abstract class Parent {
    
    abstract val paramsClass: Class<????> // should be a class that extends Params

}

class Subclass : Parent() {
    
    override val paramsClass = MyParams::class.java

}

data class MyParams : Params()

[Lukas Sztefek]

Maybe like this?

abstract class Params
class MyParams : Params()

abstract class Parent<T : Params> {
    abstract val paramsClass: Class<T>
}

class Subclass : Parent<MyParams>() {
    override val paramsClass = MyParams::class.java
}

[diesieben07]

If you don't need the concrete type: Class<out Params>

[Mark Buikema]

thanks, the out keyword was what I was looking