Sometime in the future:
"Why I should have written nanomsg in Rust, not C".
"Why I should have written nanomsg in Rust, not C".
From what I have read so far, implementing intrusive lists is not easy in Rust. (If you know of a working intrusive doubly linked list implementation in Rust 1.0 that does not invoke undefined behavior, please tell me; I'd like to know how it should be done.)
Here's what I found after a Google search, by one of the core Rust devs (unsurprisingly).
It can be used in a freestanding (nostd) environment such as a kernel. It uses unsafe code but provides a safe interface. The primary technique is to embed the type that is iterated over in a larger struct which contains the links. This way I can give out references to the inner type without fear of invalidating the iterator.
I see. I was too fixated in embedding a small struct with the links within the larger struct (in the style of the Linux kernel "struct list_head"), and didn't think of doing the opposite.
It probably makes being in several intrusive structs at the same time much more complicated, but I think it's possible to do without breaking anything.