How much compatible Kotlin generics are with Java ``` sealed class NetworkResource lt out ResponseType out ErrorType gt class Loading lt out ResponseType out ErrorType gt NetworkResource lt ResponseType ErrorType gt data class Success lt out ResponseType out ErrorType gt val response ResponseType NetworkResource lt ResponseType ErrorType gt data class Error lt out ResponseType out ErrorType gt val error ErrorType NetworkResource lt ResponseType ErrorType gt class NetworkObserver lt ResponseType ErrorType gt Observer lt NetworkResource lt ResponseType ErrorType gt gt ``` When I use it from Java I m getting `incompatible types lt anonymous NetworkObserver lt Object String gt gt cannot be converted to Observer lt NetworkResource lt Object String gt gt ` However if I am remove `out` from NetworkResource it works for Java but it messes type inference in Kotlin

How much compatible Kotlin generics are with Java ``` sealed kotlinlang #announcements

01/23/2018, 1:26 AM

How much compatible Kotlin generics are with Java ?

sealed class NetworkResource<out ResponseType, out ErrorType> {
    class Loading<out ResponseType, out ErrorType> : NetworkResource<ResponseType, ErrorType>()
    data class Success<out ResponseType, out ErrorType>(val response: ResponseType) : NetworkResource<ResponseType, ErrorType>()
    data class Error<out ResponseType, out ErrorType>(val error: ErrorType) : NetworkResource<ResponseType, ErrorType>()
}

class NetworkObserver<ResponseType, ErrorType> : Observer<NetworkResource<ResponseType, ErrorType>> {}

When I use it from Java I'm getting

incompatible types: <anonymous NetworkObserver<Object,String>> cannot be converted to Observer<NetworkResource<Object,String>>

. However if I am remove

out

from NetworkResource it works for Java, but it messes type inference in Kotlin.

It looks like some

@JvmSuppressWildcards

and looking at the bytecode do the job. I wonder if I am doing the right thing.