ARC is the reason Swift won't make it into the systems programming world. I - a firmware engineer - am glad Rust team stuck to their guns and kept it 0 overhead.

What sigils? All Rust has is & now.

Using ARC removes control from the programmer and has a significant runtime overhead (atomic reference counts), which violates Rust's zero-overhead principle. What Swift works well when you need deep Objective-C integration, of course.

Isn't that essentially what Rc<T> or Gc<T> are? Rust obviously can't get rid of the other types, since safe manual memory management is one of their core use cases, but it does support automatic memory management.

err.. Rust doesn't have neither '@' or '~' any more. And there is "std::rc::Rc<T>" in case you want reference counting. A big fat difference is that you are not forced to use it.