[pornel]

> But you can just use very similar structures yourself in C programs! You can prevent problems in C as well by construction, even when the compiler does not enforce it.

Enforcement is the point. Otherwise you're just saying people should be writing bug-free programs. "By construction" doesn't mean it's possible to construct a program satisfying a requirement, but that the compiler ensures it's impossible to violate it.

Even for a hypothetical perfectly diligent flawlessly executing programmer it's a time saver. If you want to run a 3rd party function across threads: in Rust, the compiler tells you if it's thread-safe or not, tracing through all dependencies, callbacks, checking data structures, mutexes, ref counts, etc.

And it works the other way, if I change a function that used to be thread-safe to do something unsynchronised, it won't compile any more in users' multi-threaded programs, instead of silently screwing them. Their code may have been perfectly correct before the change, and I couldn't feasibly track down everyone using my function before making a change, but having invariants in the type system automates this checking and communication.

> Just look at some of the bugs found in Rust, it is just the same old nonsense as everywhere

You're comparing your perfect self who writes flawless C on the first try with some random guy's library.

Properly designed Rust written by flawless Rust programmers is also bug-free.

Language safety is a human problem (exists to catch mistakes), and it's hard to sensibly argue whether your imaginary average C programmer is better than mine.

Rust's claims aren't absolute, so aren't disproven by a single counter-example (https://infosec.exchange/@littlealex/116838684458539473)

It's better to look at broader data, e.g. https://github.com/rust-fuzz/trophy-case - look how much lower typical severity is there.

And you can look at data from Google where they track drop in defect density in Android as it gets rewritten in Rust. I know all these top engineering companies just aren't as flawless as you are, and that's okay, Rust is for the rest of us.

[uecker]

Rust isn't perfect, this is my point. But its marketing is based on this idea ("rule out whole class of bugs"). If this were true then the bugs I cited could not exist, so they severe as counter examples that clearly invalidate this exaggerate claim. So we are back to the question to much incremental improvement it brings. The arguments you bring are essentially the same we heard before for object-orientation and other ideas. I agree that compiler enforcement helps, but the idea that this is a game changer is wrong.

I don't quite trust google's numbers and there are so many ways this could be biased. It is also not based on a comparison to modern C. One also has to realize how incredibly large the amount of C code is, which exists and with a lot also being very old and neglected. Any kind of CVE counting is highly misleading if you compare a new language with a security focus against existing projects. With more Rust code we will see more issues, especially when more average programmers use it that cut corners once they need to get things done. But I agree that this is where Rust can improve the situation, but so can modern C tooling. Wanting to put everything into the type system is a trend, but I don't think it is obviously the right step in the long run.