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0 pointsdavemp4mo ago0 comments

Rust technically isn’t a memory safe language the second you use “unsafe”. Rust advocates tend to pretend the can have their cake and eat it too when comparing it to other low level languages. No, just because you have the word unsafe next to the scary parts doesn’t make it okay.

I’ve written a good chunk of low level/bare metal rust—unsafe was everywhere and extremely unergonomic. The safety guarantees of Rust are also much weaker in such situations so that’s why I find Zig very interesting.

No oob access, no wacky type coercion, no nullptrs solves such a huge portion of my issues with C. All I have to do is prove my code doesn’t have UAF (or not if the program isn’t critical) and I’m basically on par with Rust with much less complexity.

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dvtkrlbs4mo ago

The point of unsafe is you have small bubbles of unsafe which you can verify rigorously or use tools like Miri to make sure they upheld and you build safe abstraction on top of that unergonomic part. Looking at embedded-hal and even to extreme embassy you can see the value of it. If you don't do any abstraction I definitely agree Rust is not fun to write at all.

zozbot2344mo ago

The safety guarantees of Rust the language around unsafe are just as good as C or Zig if you use the appropriate facilities (raw pointers, MaybeUninit, UnsafeCell/Cell, Option for nullability, Pin<> etc). Sometimes this is made unnecessarily difficult by standard library code that expects all the guarantees of ordinary Safe Rust instead of accepting more lenient input (e.g. freely aliasable &Cell<T>'s), but such cases can be addressed as they're found.

davempOP4mo ago

My point is that it’s easier to write correct Zig code than correct unsafe Rust. Raw pointers can be null in rust so you should use NonNull<T> but there’s aliasing rules that are easy to mess up. And difficultly with the stdlib as you mentioned.

I don’t actually mind Rust when I was able to write in safe user land, but for embedded projects I’ve had a much better time with Zig.

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