[Vipsy]

I love how it shows that you can have both performance and safety without jumping through hoops. The little details of memory management really shape how we end up writing code, often without even noticing. Rust makes it possible to get close to the hardware while still keeping you out of the usual trouble spots. It’s one of those things you appreciate more the longer you use it

[johnisgood]

Erm what? The article contradicts this. I'd push back on "without jumping through hoops". The article itself demonstrates 6 layers of abstraction (Vec<T> -> RawVec<T> -> RawVecInner -> Unique<u8> -> NonNull<u8> -> *const u8) built on unsafe primitives. The standard library does the hoop-jumping for you, which is valuable, but the hoops exist, they're just relocated.

I bet Vec's implementation is full of unsafe blocks and careful invariant management. Users face different hoops: lifetime wrangling, fighting the borrow checker on valid patterns, Pin semantics, etc. Rust trades runtime overhead for upfront costs: compile-time complexity and developer time wrestling with the borrow checker which is often the right trade, but it's not hoop-free.

The "close to hardware" claim needs qualification too. You're close to hardware through abstractions that hide significant complexity. Ada/SPARK gives formal correctness guarantees but requires proof effort and runtime checks (unless you use SPARK which is a subset of Ada). C gives you actual hardware access but manual memory management. Each has trade-offs - Rust's aren't magically absent.

[zozbot234]

It's fine https://github.com/model-checking/verify-rust-std/issues/283 https://github.com/model-checking/verify-rust-std/pull/481 (But until two weeks ago, it wasn't - you could in theory cause UB by writing purely safe code within the Vec<T> implementation.)

[johnisgood]

I had no idea, that is wild, especially considering how everyone has been outcrying "Rust is safe". Thanks for the info though.

One should wonder what else is there... but they do not wonder, they are sadly rigid with their thinking that Rust is the perfect memory safe language with zero runtime overhead.

[zozbot234]

It's not real unsoundness because it only applies within the private implementation details of Vec<T> - you still can't cause UB from outside code. But it's a real oversight that only proves how hard writing unsafe code is.

[Klonoar]

You know you can discuss languages without the weird emotional labeling from your last paragraph, right?

Plenty of people wonder. It’s part of building the language.

[johnisgood]

Fair enough.

[ozy]

Most of those are abstractions, but not a runtime overhead. NonNull even enables an optimization not available to most other languages.

And you can wonder, is this accidental complexity? Or is this necessary complexity?

[alickz]

I come from a Swift/Kotlin background and I've been learning Rust for fun in my spare time

From what I heard online I was expecting it to be a lot harder to understand!

The moving/borrowing/stack/heap stuff isn't simple by any means, and I'm sure as I go it will get even harder, but it's just not as daunting as I'd expected

It helps that I love compiler errors and Rust is full of them :D Every error the compiler catches is an error my QA/users don't

[Tade0]

The language and associated tooling keep improving.

Over the course of the last decade I've made several attempts to learn Rust, but was always frustrated with having code that reasonably should compile, but didn't and I had to run the build to even find that out.

Now we have rust-analyzer and non-lexical lifetimes, both tremendously improving the overall experience.

I still don't enjoy the fact that borrows are at the struct level, so you can't just borrow one field (there's even a discussion on that somewhere in Rust's) repo, but I can work around that.

To drive the point home: I'm a frontend developer. This is a very different environment compared to what I'm used to, yet I can be productive in it, even if at a slower pace in comparison.

[germandiago]

Rust is not the most productive language by any means... it is hardened AF if you avoid unsafe, but productive?

I can code much faster in almost any language compared to Rust. It creates mental overhead. For example, to compare it to siblings, Swift and C++ (yes, even C++, but with a bit of knowledge of good practices) lets you produce stuff more easily than Rust.

It is just that Rust, compared to C++, comes extra-hardened. But now go get refactor your Rust code if you started to add lifetimes around... things get coupled quickly. It is particularly good at hardening and particularly bad at prototyping.

They seem to be the opposite in the absence of borrowing without a garbage collector, since you need to mark the lifetime in some way.

[zozbot234]

Rust is not that bad at prototyping, you need to use the right featureset when writing quick prototype code. Don't use lifetimes, use clone() and Rc/Arc freely to get around borrow-checker issues. Use .unwrap() or .expect("etc.") whenever you're not sure how to pass an error back to the caller. Experiment with the "Any" trait for dynamic typing and downcasts, etc. The final code will still be very high-performance for prototype code, and you can use the added boilerplate to guide a refactoring into a "proper" implementation once the design stabilizes.

[germandiago]

Thanks for the advice. That makes sense I guess.

In fact, most of the time, I would favor styles like this even for not prototyping.

At the end, refactoring is also something natural. I would reserve lifetimes for the very obvious cases wirh controlled propagation or for performance-sensitve spots.

[LoganDark]

> It helps that I love compiler errors and Rust is full of them :D Every error the compiler catches is an error my QA/users don't

amen! I despise Python even though I used to love it, and that's because it's full of runtime errors and unchecked exceptions. The very instant I learned more strongly typed languages, I decided never to go back.

[zelphirkalt]

And then comes the point, where you get a scenario, which is actually, you'd think, at least, something simple, but then gets really tough to express in strongly, statically typed languages, and you might take a step back and consider for a moment, how simple it would be to express this in a language like Python, while still being memory safe.

Statically typing things is great, and I enjoy it too, when it is practical, but I don't enjoy it, when it becomes more complicated than the actual thing I want to express, due to how the type system of that particular language or third party tool (in Python) works.

[LoganDark]

I find it fun to statically prove correctness of difficult problems. To each their own, though, of course.

[germandiago]

Python properly paired with typing is very competent IMHO.

[mring33621]

I would like to learn how to do this well!

[germandiago]

Well, the ideal is to install mypy and have a linter in your editor/IDE. It will immediately highlight lots of things for you.

[LoganDark]

mypyc is also fun