slotmap VS winsafe

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

I know all that shit because I'm the author of Rust's WinSafe library, which is a safer Rust layer over native Win32, so I had to deal with a lot of shit like this.

[dependencies] winsafe = { git = "https://github.com/rodrigocfd/winsafe", features = ["kernel"] }

Externally, you can write a lot of native Windows stuff in Rust already. Personally, I'm having a lot of fun with WinSafe.

If you had such problems (which I also had in the past), I'm really interested in you opinion about WinSafe, and if it could help you solving them.

If you're after a native Windows application, WinSafe may suit your needs.

As the author of WinSafe, I can say it's tedious sometimes, but it's often very challenging, because you have to translate crazy unsafe behaviors into Rust's ownership model. It's surely hard, but also very rewarding at the end.

As the author of the WinSafe lib, I wholeheartedly agree.

I don't know how rare this is (or how rare it should be), but this issue warned me about this potential problem, and I had to make a huge refactoring to treat the possibility. I had to rethink many aspects of all handle implementations. It was hard work, but in the end it was worth it.

WinSafe says hello.

WinSafe, for example (which attemps to be a safe layer over the Windows API), provides lots of RAII automations. A fine example is the BeginPaint function: