slotmap

> Rust also hides allocation. Does it? In Rust you allocate by calling a function. That's exactly the same as C. Are there any langauges that don't allow you to hide allocation behind a function call? > So what you say is definitely true if you do an allocation heavy, heap fragmenting, RAII style of programming. I don't think Rust encourages lots of small allocations. Most of the Rust code I work with does a lot of arena allocation (using crates like https://github.com/orlp/slotmap) and reusing of allocations. And for that matter a lot of stack allocation avoiding the heap entirely. And it's borrowing system is fantastic for working with shared pointers to data without having to worry that something might accidentally overwrite it. > You're also completely glossing over the incredible complexity you get in all thee weird intersection of r

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 i

Similar to the second approach, you can have better ergonomics and performance by using a memory arena library like slotmap. A doubly linked list implemented using slotmap: https://github.com/orlp/slotmap/blob/ce6e1e02bb2c2074d8d581e...

I'm the author of slotmap (https://github.com/orlp/slotmap) briefly mentioned at the end. I'm working hard on the requested 'independent allocation' (or secondary maps as I'm currently leaning on), and will have it ready soon.