Comment by dwattttt

I'm not super certain you're interested in answers, but assuming good faith:

> https://github.com/rust-lang/rust/blob/main/library/core/src... How large a percentage of the logic code there is inside of an unsafe block?

The claim isn't "there's no unsafe". You've linked one file out of an entire stdlib; it uses unsafe to implement its algorithm, and of all the Rust code that could exist, this has one of the highest requirements for being maximally performant.

Now if you'd said "most of the Rust std library is unsafe", or "most Rust code is unsafe, you'd have a good rebuttal. But that's not the case.

> And, if you have an unsafe block that is 100% correct, but it relies on safe code being correct, do you need to vet all that safe code? Potentially whole modules needing to be vetted?

Then the unsafe block is not 100% correct. I can slap a wrapper around memcpy and call it "safe", and say that if anyone passes wrong parameters it's their fault. Rust as a language says I'm at fault for saying it's safe though.

> Is unsafe Rust code generally harder to get correct than code in other languages, due to...

Harder than other systems programming languages? Having worked in a fair few, I disagree. Harder than "higher" level languages? Some of them yes, some of them no; I've seen "simple" languages admit very poor architectures, and fall in a "safe" heap when the project has to grow.

> Do Rust libraries, including std, historically have had UB bugs? https://materialize.com/blog/rust-concurrency-bug-unbounded-...

Are you suggesting this is a bar a language should achieve? Some examples of this would be interesting.

As for the rest, I don't think anything meets this bar you're setting. Certainly not languages that would otherwise be used where Rust is.