They’re not the same thing; Swift is “automatic” and Rust is “atomic”; Swift’s ARC is implemented the same way as Rust’s Arc, but Rust’s is manual.

Hi! I think you may have repeated what I said in my comment, that the letter "a" stands for different things. Although they do the same thing: they are both atomic (in the sense of concurrency) and automatic (in the sense that you do not have to explicitly retain or release objects).

That’s the thing: they’re not automatic in Rust. You have to explicitly retain. (Release is automatic though.)

Furthermore, in Swift it’s pervasive, and in Rust, it only happens for types that explicitly opt-in.

It sounds automatic to me. Maybe we disagree about what "automatic" is.

It also sounds like you are hunting for ways in which Swift and Rust are different. This is completely unnecessary! It turns out that I already know that they are different languages, and that the features do not map exactly 1:1 to each other. I hope next time you give me a little credit.