I understand the source of the sentiment, but also disagree with it. I've been writing Rust code for years and have never had occasion to write my own custom data structure, and (discounting FFI) I've reached for the `unsafe` keyword like twice (which I think I ended up removing anyway, because I was trying to be too clever).

But then again, my background is in higher-level languages (Java, Python) where writing data structures isn't your usual beginner task. I sympathize with C programmers to whom a linked list is the go-to toy learning program, but the urge to resort to unsafe shenanigans to implement self-referential data structures doesn't reflect the typical experience of using the language.

And for those who still wish to persist, may I recommend the book "Learning Rust With Entirely Too Many Linked Lists": http://cglab.ca/~abeinges/blah/too-many-lists/book/