Unfortunately its CMOS battery ran out and when I went in to replace it I had to unplug a few ribbon cables which of course promptly snapped the now-brittle plastic connectors. Its been sitting on a shelf waiting to be revived once again ever since... I miss that little thing.

Also, fun fact: Rust cannot remove anything from std once stabilised, presumably forever. Take this with a slight grain of salt, I haven't vetted this thought myself, but it's what I hear from Rust project people and I've just been in the project all-hands for three days.

Rust does partially have an easier time since it eg. does not guarantee the ABI of various std types like Vec (although the size and alignment are probably guaranteed at this point), and with 1&mut XOR N& providing local reasoning and isolation you get to change internal details easier.

I guess the answer is "no".

In Nova JavaScript engine[1] I've done exactly as you've done and split objects into typed side pools (I call them "(typed) heap vectors") but in a JavaScript engine my _hypothesis_ is that the visitation patterns are much more amenable to this: an Array, Set, or Map is more likely to be homogeneous than heterogeneous, and therefore a loop over the contents is likely going to hit the same side pool for each entry.

[0]: https://www.youtube.com/watch?v=s_1OG9GwyOw [1]: https://trynova.dev/

The Kansai airport immigration office uttered a lot of "oohs" and "eehs", but they came through and in less than 45 minutes my appeal for deportation was accepted and I was granted a 1 year student visa. Always makes me happy when I pass through there :)

[1]: https://rust-lang.github.io/rust-project-goals/