Also, one of the easiest ways to leak memory in Rust. My understanding is that substructural typing systems are just not quite powerful enough to represent the semantics of double-linked lists, but I don't understand the math myself.
Obviously it won't leak memory if you do it correctly, but Rust will happily let you leak memory in an Rc<T>.
If you really do want to leak memory, Rc<T> is overcomplicated - just call `Box::leak` and throw away the output.
Rc<T> is the preferred way to introduce unintentional memory leaks.