[steveklabnik]

There is a weak_ptr equivalent; the borrow checker makes it basically impossible to use references to implement it. You can still do it with raw pointers exactly like you would in C++ too.

(And yes, it's a niche data structure, vecs are far more common, but it's people's go-to "the borrow checker restricts you too much" example anyway.)

[DerDangDerDang]

Thanks, that’s illuminating.

Seems a counter productive go-to argument given the amount of effort we (c++ coders) generally put in to avoiding non-adjacent memory access :)

[steveklabnik]

You would think so, but it's sort of just become a standard thing on forums, someone claims that linked lists are impossible, someone else talks about how you can do them in various ways (possibly linking to the "Learning Rust with Too Many Linked Lists" book, which is awesome, by the way), and how you don't actually need them in real code, followed by someone saying that this is just Rust stockholm syndrome and they use linked lists all the time... just the fun of being on forums :)

[DerDangDerDang]

Haha, forums gonna forum I guess. Reminds me of the “but how can I trust std containers to allocate for me? Anything could happen!” crowd in the 90s and early 2000s.

FWIW I think the Rust community has done itself a disservice by focusing on the safety benefits. Const by default and move by default are much bigger deals in the day to day coding experience, but it’s hard to get across just how awesome they are.

That book looks great, thanks - should take me through a few corners I’ve yet to meet while keeping me entertained.

[steveklabnik]

You're welcome. I sorta kinda agree on the safety thing; I wrote a blog post that kind of kicked off a whole discussion about this a while back; https://brson.github.io/fireflowers/ is a really beautiful summary of all of that.

[DerDangDerDang]

That was a wonderful read.

After 20 years of C++ and about the same number of hours of Rust, Rust makes me feel like Fire Mario because when I come to do a strict correctness and memory efficiency pass after writing something - it’s already correct. I suspect this will have a compound interest-like effect, similar to good code coverage empowering change.