I would pick C++ for anything to do with high-performance linear algebra. There are a few other domains (desktop GUI, CAD) where I don't trust the Rust library

I would pick C++ for anything to do with high-performance linear algebra. There are a few other domains (desktop GUI, CAD) where I don't trust the Rust library ecosystem. But, yeah, there are a ton of domains (notably embedded) where I would want Rust.