[mrtngslr]

I actually haven't tried this... do you know off the top of your head what it takes to make a cycle with Rc?

It should not be possible with normal borrows (and safe Rust) since they're statically checked to be acyclic.

[jamincan]

The Rust Book has an example: https://doc.rust-lang.org/book/ch15-06-reference-cycles.html

Of course, leaking memory is as easy as using `Box::leak`, although that's probably never going to happen accidentally.

[britneybitch]

You could store a `RefCell<Option<T>>` in an `Rc` and set it to `Some(rc)` after creation.

Or you could use the recently-stabilized `new_cyclic` method: https://doc.rust-lang.org/std/rc/struct.Rc.html#method.new_c...

[bitexploder]

And when using C libraries / FFI, there are a lot of tricky things going in, it is much easier to leak in unsafe land.