[meindnoch]

Ummm… No.

Swift structs are just like C structs (from a memory perspective). The copy-on-write thing is implemented manually by storing a private refcounted object in your struct. See the implementation of Array for example: https://github.com/apple/swift/blob/main/stdlib/public/core/...

There’s no magical copy-on-write mechanism at the language level.

[jshier]

I don't know why this is downvoted, it's true. There is no automatic copy on write optimization in Swift. It's a manual optimization that expensive types like Array implement manually.

[meindnoch]

>I don't know why this is downvoted, it's true.

I know, right? Some people are pretty insecure…