slotmap VS min-sized-rust

It looks like .get_disjoint_mut() from slotmap failed under stacked borrows, but seems to pass under tree borrows

I think slotmap is meant to solve this exact issue. Basically when you insert into a collection you get an Id:Version tuple as key. When you reuse a slot, next time the key will be Id:Version+1 and when you try to access the removed value by using Id:Version, it will return None. You can think about it as delayed invalidation.

Dunno about existing implementations, but it looks like it's a feature they'd accept: https://github.com/orlp/slotmap/issues/73

It's actually quite easy.

You can use either slot map or slab to side step rust borrow checker. Example https://github.com/orlp/slotmap/blob/master/examples/rand_meld_heap.rs

I don't know, only have some theories.

1. The name isn't particularly catchy or descriptive. It is the correct name for the data structure, but not too many people know the data structure.

2. People don't even know what they're missing. It's not a very Google-able problem to begin with. Slotmap provides an interesting solution to (circular) ownership and safe allocator / weak pointer design problems, but people don't recognize that they're having them or that slotmap could help.

As an example of this, the doubly linked list example (https://github.com/orlp/slotmap/blob/master/examples/doubly_...) can safely remove nodes from the linked list given their handle, in O(1), even from the middle, completely safely and correctly, even in the presence of double deletions or ABA memory re-use. You can't replicate this with just pointers, without introducing heavy refcounting solutions.

Nope, it's perfectly safe: https://github.com/orlp/slotmap/blob/master/examples/doubly_linked_list.rs.

I think keeping the relationship between child and parent elements in the node graph might be better accommodating better via a psuedo-ECS system, see https://www.reddit.com/r/rust/comments/cnjhup/idiomatic_way_to_reference_parent_struct/. The https://github.com/orlp/slotmap crate looks promising. I think I'm just going to ditch the global shared HashMap in favor of something that can better accommodate child/parent relations.

I think the slotmap crate is similar to what you're trying to write: https://github.com/orlp/slotmap

This is a good guide on building small Rust binaries: https://github.com/johnthagen/min-sized-rust

This talks about going to extreme lengths on making the smallest Rust binary possible, 400 bytes when it was written, https://darkcoding.net/software/a-very-small-rust-binary-ind...

The thing is, you lose a lot of nice features when you do this, like panic unwinding, debug symbols, stdlib… for kernel and some embedded development it’s definitely important, but for most use cases, does it matter?

Oh it was 137, haha. I will link you to this older comment of mine: https://news.ycombinator.com/item?id=29408906

See also https://github.com/johnthagen/min-sized-rust

Are you sure? If so then this is awesome news, but I'm a bit confused; the commit in that min-sized-rust repo adding `build-std` to the README was merged in August 2021: https://github.com/johnthagen/min-sized-rust/pull/30

Are you saying that at that point the feature still hadn't "landed in Rust nightly" until recently? If so then what's the difference between a feature just being available in Rust nightly, vs having "landed"?

Rust binaries are by default nowhere close to 500MB. If they are not small enough for you, you can try https://github.com/johnthagen/min-sized-rust. By avoiding the formatting machinery and using `panic_immediate_abort` you can get about the size of C binaries.

A useful reference: https://github.com/johnthagen/min-sized-rust

That must be without stripping. Also there are ways to reduce binary size. See e.g. [min-sized-rust](https://github.com/johnthagen/min-sized-rust). I've gotten stripped binaries of small cli utils less than 400KiB without doing anything special, less than 150 KiB by customizing profile settings and compressing with upx, and less than 30 KiB by replacing the std with the libc as the link shows. Haven't tried with fltk though...

This is not quite what you're asking, but it does also address the underlying concern: https://github.com/johnthagen/min-sized-rust