do you have any sense for how this would integrate with rust? as someone who isn't familiar with how it works, it's not clear whether that would be as easy as normal C ffi interop or more involved.
Oh man that was a fun hack to write. Basically we demonstrated an easy-to-setup AD on rust by leveraging link-time optimization (LTO) as a way to make sure Enzyme's generate derivatives "optimization pass" was run.
We're currently working with the Rust ML infrastructure group to make a nice integration of Enzyme into Rust (e.g. nice type-checking, safety, etc). If you're interested in helping, you should join the Rust ML meetings and/or Enzyme weekly meetings and check out https://github.com/rust-ml/Meetings and https://github.com/tiberiusferreira/oxide-enzyme/tree/c-api . There's a bunch of interesting optimizations and nicer UX for interoperability we want to add so more manpower is really helpful!
The most interesting thing from the Rust standpoint is that ideally we'd want Enzyme to be loaded into the Rust compiler as a plugin (much like it is for Julia, Clang for C/C++, etc) -- but Rust doesn't support the option for that yet. This means we can either help push for plugins/custom codegen in Rust, make script-based compilation tools within rustc [I don't remember the specific name but someone who is more of a Rust expert I'm sure can chime in], or do the sketchy LTO approach above [not always desirable as it requires running LTO].
Alternatively Enzyme can just become part of LLVM mainline so everyone can use it without a plugin :P We're not quite there yet but we're in the process of becoming a formal LLVM incubator project!
