# "Actors are reference types, but why classes?"

**URL:** <https://forums.swift.org/t/actors-are-reference-types-but-why-classes/42281>\
**Category:** Pitches\
**Created:** [November 25, 2020, 6:48pm UTC](https://forums.swift.org/t/actors-are-reference-types-but-why-classes/42281 "2020-11-25T18:48:22Z")\
**Posts on this page:** 1\
**Showing post:** 94

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**Author:** ![michelf](https://sea2.discourse-cdn.com/swift/user_avatar/forums.swift.org/michelf/32/1180_2.png) [@michelf](https://forums.swift.org/u/michelf)\
**Post date:** [December 10, 2020, 2:17pm UTC](https://forums.swift.org/t/actors-are-reference-types-but-why-classes/42281/94 "2020-12-10T14:17:48Z")

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> [@Karl](#):
>
> The problem with using inheritance to bring other data in to your isolation domain is that it doesn’t scale: what if there are 2 actors (usable on their own) that I wish to synchronise with? We don’t support multiple inheritance.

Inheritance can work in some case, but you're right that it doesn't scale.

This discussion has given me an idea of how we could allow some form of composition with synchronous access for actors. But it's a bit out of scope for this thread. So I wrote a pitch: [Interlocking in a Hierarchy of Actors](https://forums.swift.org/t/interlocking-in-a-hierarchy-of-actors/42695)

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