Comment by vvanders | Hacker News Reader

Comment by vvanders | Hacker News Reader

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Shared ownership is code smell to me regardless of the language, I think Rust just makes it a bit more high friction.

Language difficulty I'm having trouble seeing how C++ isn't harder there. You have decades of features, lots of gotchas that I could rattle off and a bunch of implicit behavior that you only learn about when it blows up at runtime(if your lucky). Heck, I've seen heap corruptions stay latent in codebases for 6+ months only to have a new field added that causes them to cascade into a failure that took 3 weeks to debug across 2 different teams. I've still seen modern compilers not catch basic use after free scenarios in code today.

I won't disagree that you can get code to compile quicker in C++ but if your goal is feature velocity you're better served by a high level language. If your goal is stability, performance and memory which is the domain of systems programming then I think C++ has a bunch of hidden failure modes that Rust frontloads in an elegant way.

There are projects where you'd pick C++ for portability on platforms LLVM doesn't support or momentum with existing codebases but if I had to pick between the two my personal bias is towards Rust for all the reasons above.

> Shared ownership is code smell to me regardless of the language

This is an unsubstantiated claim. If Rust makes something hard, that doesn't automatically make it universally bad. Nearly every large Rust code base I've seen uses reference counting (both `Rc` and `Arc`) a lot. Moreover, it is not practical to write general-purpose code avoiding both GC and RC because the need for shared ownership will inevitably crop up at some point. So ruling it out as code smell is a bit dogmatic.

It is also worth noting that ownership semantics is one approach (among others like GC) to memory management. In future, more languages will have some sort of ownership semantics along with GC. Nim's ORC is currently a good example.

Let's keep this on track; we're only talking about the learning curve here.

Nobody here is saying c/c++ or rust is better after their respective learning curves. No need to be defensive, they're just languages, and every language has its strengths and weaknesses.

To the point: modern c++ is easier to learn nowadays. shared_ptr and unique_ptr are as easy as Rc and Box, but without the borrow checker making things harder. One doesn't have to deal with the decades of difficulties when learning c/c++. One can choose to dive into a terrible legacy c++ project just like they can dive into an unsafe mess like Actix, but thats hardly a reflection on how easy to learn a language, just the codebase you're learning from.

And rust's front-loading of problems is a great thing! It also makes it harder to learn, which is the point here.

I think we're working from different definitions of learning curves. I include in the learning curve understanding your memory ownership model, not introducing use after free, heap corruption or other failure modes.

I would argue that if you don't understand the ownership of your data you don't really understand C++(or C) and you're still learning the language. That's usually the big shift I see when developers who have a background in higher level languages moving down to C++. I've seen plenty use after free and heap corruption happen in C++0x11 and onward codebases both staying completely within modern best practices and when code diverges since there's no guardrails(ex: std::string::c_str, std::unique_ptr::get and the like).

Once you include all the footguns that exist(yes, even in modern C++) and the legacy parts of existing codebases or code that diverges from modern C++ that's why I think it has a much higher learning curve to be producing code that is at the same quality as a passing compile from Rust in aggregate.

That's reasonable; one's threshold of "safe enough" factors in.

If one is just designing a game, or a command line tool for internal use, one needn't make it completely rock solid, and C++ has the better learning curve.

If one includes the requirement to make it safer, Rust has the better learning curve.

And then if someone actually values memory safety, they use a GC'd language and laugh at how many engineer-months and proofs it will take us to make code as safe as theirs. Sigh, such is life...

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