It looks like this project is using typed arenas a fair bit - https://github.com/SomewhatML/sml-compiler/blob/master/crates/sml-core/src/arenas.rs https://githu

It looks like this project is using typed arenas a fair bit - https://github.com/SomewhatML/sml-compiler/blob/master/crates/sml-core/src/arenas.rs https://github.com/SomewhatML/sml-compiler/blob/master/crate... I don't know the details of how this is being used in the project, but it might be worth investigating.