I have a fair amount of experience with `cxx`, and even with `autocxx`. These tools show a lot of promise but are nowhere in the ballpark of `pybind11` in features, maturity, flexibility, or ease-of-use. It's early days on the Rust <-> C++ journey, which I appreciate might not be a huge concern for a lot of folks, but I depend on a lot of existing C++. My in-house thing ("alloy") is a big mess of `bindgen`/`cbindgen` and pain. It works ok but it's super counterintuitive at best that I budget like 5x the time to hoist something core up into Rust and I do for Python.
I'm excited to see what happens in the space!