[steveklabnik]

Using Rc doesn't sound like an intrusive list to me. Personally I find tons of Rcs to be messy, so I'd agree with you.

> what performance cost Rust code pay due to inability represent cyclic structures efficiently?

You can still write the code you'd write in C with unsafe. There's no inherent loss left on the table.

Furthermore, a lot of C folks reach for intrusive lists because it's easy in C, but that doesn't mean that it's always the most performant. See https://bcantrill.dtrace.org/2018/09/28/the-relative-perform... as an example of this phenomenon.