Ndtyjky

I'm trying to initiate the RoomAlarmRepository inside the RepoInit 1 & 2.

The first one says "Type mismatch", and wouldn't let me compile. That is, unless I cast it like in RepoInit2, at which point it tells me that the cast is unchecked.

class RepoInit1(app: App) {

internal val repo: AlarmRepository<AlarmModel> = RoomAlarmRepository(app.database)

}



class RepoInit2(app: App) {

internal val repo: AlarmRepository<AlarmModel> = RoomAlarmRepository(app.database) as AlarmRepository<AlarmModel>

}





class RoomAlarmRepository(val database: AppDatabase) : AlarmRepository<RoomAlarmModel> {



}



class RoomAlarmModel : AlarmModel {





}

I'm currently using the second one, as it actually works. I know I'm missing something where I declare the variable, but I'm not sure what it is.

Declare the generic type it with the out modifier as covariant.
See here https://kotlinlang.org/docs/reference/generics.html for details.

class RepoInit2(...) {

    internal val repo: AlarmRepository<out AlarmModel> = RoomAlarmRepository(...)

}