Why aren't `data` and `inner` modifiers to `class...

# getting-started

[dave08]

Why aren't data and inner modifiers to class compatible together?

[Joffrey]

I have never given it much thought, but I'd be interested in knowing your use case for needing both

[dave08]

I need to set up a TestFixture class that uses repos in the outer test class to add the fields (entities with relations) to the dbs in the init block... if I put the data class inside the test's init block before the tests, it has access to the test class's properties, whereas if I put it after, I have to make it into an inner class, then I can't do :
val (client, order) = TextFixture() unless I implement my own componentX functions...

[ephemient]

inner classes work by having a extra hidden reference to the outer class, inserted into every constructor, which I suppose could be implemented on a data class, but feels very strange

[ephemient]

moreover, given

class Foo { inner data class Bar(...) }

should Foo().Bar(...) == Foo().Bar(...) with different outer references that aren't publicly accessible on Bar itself?

[dave08]

Interesting, thanks for the explanation! I still think it might be useful though... I wonder if anyone would expect those to be equal, though. I think even though i componentX and field list the outer class ref isn't there, it should still not be equal in the end.

[ephemient]

makes sense but it's inconsistent with existing behavior

data class Foo(val bar: Int) {
    var extra = 0
}
Foo(0).apply { extra = 1 } == Foo(0).apply { extra = 2 }