Kotlin Inheritance / Declaration with Generics
up vote
2
down vote
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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.
generics inheritance kotlin
asked Nov 10 at 17:45
sofakingforever
302110
add a comment |
up vote
2
down vote
favorite
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.
generics inheritance kotlin
asked Nov 10 at 17:45
sofakingforever
302110
add a comment |
up vote
2
down vote
favorite
up vote
2
down vote
favorite
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.
generics inheritance kotlin
asked Nov 10 at 17:45
sofakingforever
302110
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.
generics inheritance kotlin
generics inheritance kotlin
asked Nov 10 at 17:45
sofakingforever
302110
asked Nov 10 at 17:45
sofakingforever
302110
asked Nov 10 at 17:45
sofakingforever
302110
asked Nov 10 at 17:45
sofakingforever
302110
asked Nov 10 at 17:45
sofakingforever
302110
302110
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
up vote
2
down vote
accepted
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(...)
}
answered Nov 10 at 18:26
Rene
1,13615
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
2
down vote
accepted
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(...)
}
answered Nov 10 at 18:26
Rene
1,13615
add a comment |
up vote
2
down vote
accepted
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(...)
}
answered Nov 10 at 18:26
Rene
1,13615
add a comment |
up vote
2
down vote
accepted
up vote
2
down vote
accepted
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(...)
}
answered Nov 10 at 18:26
Rene
1,13615
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(...)
}
answered Nov 10 at 18:26
Rene
1,13615
answered Nov 10 at 18:26
Rene
1,13615
answered Nov 10 at 18:26
Rene
1,13615
answered Nov 10 at 18:26
Rene
1,13615
1,13615
add a comment |
add a comment |
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