About @Parcelize. If I understood correctly, Kotlin compiler can implement Parcelable in existing class. But what about parcelable wrapper, e. g.

class ParcelSomething(val something: Something) : Parcelable {...

, where

Something

is not parcelable itself?

There is something for a

CustomParceler

annotation in the KEEP, but it doesn't look like it's been implemented [yet]: https://github.com/Kotlin/KEEP/blob/master/proposals/extensions/android-parcelable.md#per-property-and-per-type-parcelers

'Custom' means 'hand-written', isn't it?

What would the alternative to hand-written be? EDIT: Oh I see what you mean. No, the compiler can't implement

Parcelable

on arbitrary existing classes. It can only do so for your own classes annotated with

@Parcelize

.