Hacker News Reader

Comment by baokaola | Hacker News Reader

There's only one language that's more dangerous than C and that is unsafe Rust. I say that only half-jokingly.

It's true and I write Rust and love it dearly. There is an entire book about working with the unsafe keyword and its aliasing rules: https://doc.rust-lang.org/nomicon/working-with-unsafe.html

What do you mean?

C is unsafe 100% of the time. Rust is only unsafe in unsafe{} blocks.

This is nonsense. There is quite a subset of C which is perfectly safe and an even larger one which can easily be safe with tooling. You could argue that unsafe keyword is easier to spot than the unsafe features of C, so that makes it somewhat easier to screen for issues. But if you screen for memory safety only, this is problematic anyhow.

Good job falling for the Zig propaganda. I say that half-jokingly.

EDIT: You can't be serious people. Rust unsafe is safer than C, if for nothing else, for knowing which pointers are aliasable.

This isn't propaganda, the Rust compiler's rules when using the unsafe keyword are difficult to uphold, which is why the community wrote Miri.

Ok, and how does, in your opinion, compiler rules enforcement work in an unsafe block?

And how does Miri help solve this issue?

> Ok, and how does, in your opinion, compiler rules enforcement work in an unsafe block?

By the engineer's wit of course!

> And how does Miri help solve this issue?

By detecting undefined behavior caused by violation these rules

Is there a "Rust compiler's rule" you can point to that's harder than avoiding UB in C or C++ in similar circumstances? They strike me as very similar beasts.

> By the engineer's wit of course!

Seeing how the Rust compiler isn't an LLM, it can't really work on wit.

From the POV of a programmer, how would you implement an unsafe block? What is disabled vs what's enabled?

> By detecting undefined behavior

Say you are tasked with making Miri; how do you detect violations of these rules?

Reply on news.ycombinator.com