CODEWITHSUNDEEP
androidgenericskotlin
Abhishek Tiwari
Abhishek Tiwari

Reputation: 936

Type argument required for a class while extending in kotlin

So my problem is simple, In java if i have a base class like this:

BaseViewModel.Java 

public abstract class BaseViewModel<N> extends ViewModel {

I can extend this class to other classes without defining the generic argument N, like this:

public class BaseFragment<V extends BaseViewModel> { //this is fine

but kotlin throws an error with this approach asking for the generic definition.

class BaseFragment<V: BaseViewModel>: Fragment() {// one type argument expected

how to avoid this?

Upvotes: 0

Views: 1103

Answers (1)

hluhovskyi
hluhovskyi

Reputation: 10106

Kotlin doesn't allow to use raw types as Java does. Thus, you have to specify some type for your V : BaseViewModel:

class BaseFragment<V: BaseViewModel<Any>>: Fragment() {

It is equivalent for your Java code cause V extends BaseViewModel basically means V extends BaseViewModel<Object>

Upvotes: 3

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