Linked Lists

A few data structures implemented using a linked list (in Rust, btw).

1. A bad singly-linked stack.
2. An ok singly-linked stack.
3. A persisten singly-linked stack.
4. A bad safe double-ended queue.
5. An ok unsafe double-ended queue.
6. A production unsafe double-ended queue.
7. A double singly-linked list.
8. A stack-allocated linked list.