Support MongoDB ObjectId field type

[rorbech]

We should support the MongoDB ObjectId field type: https://docs.mongodb.com/manual/reference/method/ObjectId/

[sdeff]

Any updates about when we can expect support for ObjectId?

Or is there a workaround which allows using a RealmObject with ObjectId as primary key within a Kotlin Multiplatform app?

[tylergannon]

@sdeff what about defining your own value class ObjectId(val id: ByteArray), then the database column will contain compatible data for when the feature is released? It's hacky but might get you going?

you can expect the constructors and implement them by delegating to the org.bson.types.ObjectId implementation.

expect fun ObjectId(): ObjectId
expect fun ObjectId(hexValue: String): ObjectId

Untested so ymmv. I'd be curious if someone more knowledgable than this relative noob could say a priori that it won't work.