`requireNotNull` does not provide smart cast null safety Is there another way to concisely mark null as Illegal state and have smart cast ```private var id Long = null override fun delete = runBlocking requireNotNull id notesRepository deleteNote id id is not smart cast to not null ```

the id should tell you when you have a blocks like ```if id = null notesRepository deleteNote id ``` it should warn you that it cannto smartcast `id`

`requireNotNull` does not provide smart cast null safety Is kotlinlang #announcements

06/10/2021, 11:41 AM

requireNotNull

does not provide smart cast null safety. Is there another way to concisely mark null as Illegal state and have smart cast?

private var id: Long? = null

override fun delete() = runBlocking {
    requireNotNull(id)
    notesRepository.deleteNote(id!!) // id is not smart cast to not null
}

Hasan Hosgel (alosdev)

06/10/2021, 11:45 AM

it would work if id is a parameter of the function or you put the result of require into an value and use it

Petter Måhlén

06/10/2021, 11:46 AM

notesRepository.deleteNote(requireNotNull(id))

06/10/2021, 11:49 AM

is id a var ?

requireNotNull should smartcast, but it won't be able to for

var

that could change between the check and the usage

06/10/2021, 11:51 AM

@Nikky Oh I see

06/10/2021, 11:52 AM

the id should tell you when you have a blocks like

if(id != null) {
    notesRepository.deleteNote(id)
}

it should warn you that it cannto smartcast

id

another way to solve similar problems is to assign them to a val in that scope via

let

or similar scope functions but best would be if you can get rid of the

var

.. or change it into a parameter.. which also makes it immutable in the scope of the function

06/10/2021, 11:56 AM

@Nikky Yes that makes sense. thank you