[steveklabnik]

Refcounting and tracing are two different forms of GC, but you're right in the sense that most people mean tracing.

At the same time, we're putting a lot of thought into how to properly add an optional tracing GC. It's important that it doesn't impact the no-GC case, which is still, of course, primary.

[filsmick]

I'm glad to know there is ongoing work on a tracing GC. Rust has many strengths aside from lifetimes and ownership (algebraic data types, sane generics, strong module support, very strong type system), so a few features to make it more usable for use in contexts where performance isn't as important as expressivity would be very nice to have.

[Jweb_Guru]

IMO, "contexts where performance isn't as important" aren't very relevant to Rust (hence why I'm strongly against, for example, hardcoding a global GC into the language, or splitting the language into a GC'd and non-GC'd half). But I do understand why some people would like to use the same language for all these use cases, I suppose.

[Rusky]

I don't think the primary use case for a GC in Rust would be "contexts where performance isn't as important" so much as another tool for lifetime management.

The current reference counted types don't just get used for convenience, they get used because they describe the actual life cycle of the data they contain. A tracing GC would be similar.