Comment by lukax

Do not write the bindings manually. Just use the amazing uniffi-rs library from Mozilla.

https://github.com/mozilla/uniffi-rs

You can generate bindings for multiple languages. It supports error handling on both sides and latest versions also support native async integration.

I've used it to reuse the same Rust engine in iOS and Android apps and write native UI.

https://github.com/koofr/vault