I don't think this is a great example of "sound C program turning into unsound Rust program". The crate isn't "unsound" in the way a C program would be - it's u

I don't think this is a great example of "sound C program turning into unsound Rust program". The crate isn't "unsound" in the way a C program would be - it's unsound in the sense that, given either 'unsafe' elsewhere or changes to how Rust constructs work (that are not guaranteed) a consumer of this crate could accidentally violate one of the necessary guarantees. For a Rust program the bar is "has to be safe, even if some other part of the program uses unsafe". That seems like it's arguably a higher bar than C where everything is already "unsafe" in that same way.