Due to potential new direction of D, I’m looking for some escape route just in case. I’m primarily a gamedev, so no functional programming languages like Rust or Haskell. Also one of the features I dislike the most in C/C++ is the super slow and super obsolete precompiler with its header files, so no zig, I don’t want to open two files for editing the same class/struct. Memory safety is nice to have, but not a requirement, at worst case scenario I’ll just create struct SafeArray<Type>. Also I need optional OOP features instead of reinventing OOP with all kinds of hacks many do when I would need it.
Yes I know about OpenD, and could be a candidate for such things, just looking into alternatives.
Talk to Tim Sweeney.
The Next Mainstream Programming Language: A Game Developer’s Perspective (pdf).
Note that C++ is getting modules, that might speed up compilation, though it’s still C++ afterwards. The cool kids in systems programming are using Rust now. I have no idea if game devs are using it. Anyway, on games projects or anything else, you have to use what the other people on your team are using, which these days is still mostly C++ afaict.
It’s not fully there yet for production use, but there is certainly interest:
One thing to note about Rust for gamedev is that it enforces correctness to a degree which makes it cumbersome for prototyping.
Using it with an ECS already alleviates a lot of that pain (by sidestepping Rust’s memory management). And I do imagine, much like in C++, that more and more abstractions will be built on top of it to eventually make it very nice to use.
But yeah, Rust isn’t as clear-cut of an upgrade yet, as it is in some other fields.
What’s an ECS?
It’s the “Entity-Component-System architecture”, consisting out of:
It’s kind of a competing strategy to OOP. It offers better performance and better flexibility, at the cost of being somewhat more abstract and maybe not quite as intuitive. But yeah, those former two advantages make it very popular for simulations / gamedev. Any major game engine has an ECS architecture under the hood, or at least something similar to it.
Entity Component System. See Bevy for an example of an ECS game engine in Rust.
Using “clever” ways to disable the borrow checker is one of the few things I don’t like about rust. I much rather it having a “borrow checker version” and a “garbage collector version”. That way we could rapidly iterate through design choices with the GC, and once the design has proven good, apply lifetimes and such to use with the borrow checker. The only downside to this I can think of is that most would just leave it in the GC version and not bother to move to borrow checker. But that’s fine by me, rust has many other features to take advantage of. As long as no GC libraries are allowed in crates.io, it should be fine.
Yeah, I don’t think that can happen without splitting the whole ecosystem in half. Garbage collection requires a runtime, and tons of the code semantics are also just different between the two, particularly with asynchronous code.
I also imagine that many people wouldn’t just leave their particular program in the GC version, but never even bother to learn the ownership/borrowing semantics, even though those largely stop being painful after a few months.
But yeah, I actually don’t think it’s too bad to have individual parts of the ecosystem using their own memory management strategies.
The two examples that I can think of are ECS for gamedev and signals/reactivity for UI frameworks. Which is what is used in C++ or JavaScript, Kotlin, too. You’d probably still want to use these strategies, even if you’ve got garbage collection available…
I’ve re-thought about the problem and I think for prototyping I should just Box::leak() and work with raw pointers.
This approach also doesn’t allow you to not learn the borrow checker, since leaking everything is not a good memory management strategy, but might be fine for rapidly iterating on a design.
EDIT: maybe use a leak!() Macro that does Box::leak(Box::new()) in debug mode but panics on release (as long as you execute once in release it should be fine).
I tried something like that once. Basically, I was trying to create an API with which sysadmins could script deployments. That involves lots of strings, so I was hoping I could avoid the
Stringvs.&strsplit by making everything&'static str.And yeah, the problem is that this only really works within one function. If you need to pass a parameter into a function, that function either accepts a
&'staticreference which makes it impossible to call this function with an owned type or non-static reference, or you make it accept any reference, but then everything below that function has normal borrowing semantics again.I guess, with the former you could
Box::leak()to pass an owned type or non-static reference, with the downside of all your APIs being weird.Or maybe your prototyping just happens at the top and you’re fine with making individual functions accept non-static references. I guess, you’ll still have to try it.
Since you’re already at the bargaining stage of
griefprogramming, maybe you’re aware, butRcandArcare the closest you can get to a GC-like feel. These do reference counting, so unlike GC, they can’t easily deal with cyclic references, but aside from that, same thing.Unfortunately, they do still have the same problem with passing them as parameters…
The good thing about Box::leak() is that it returns a raw *mut pointer. So you need unsafe{} to dereference it. Might as well:
let my_ref = &mut unsafe{*ptr};while you are at it, so you have a perfectly normal rust reference, so the function signatures don’t need any change.The problem with Rc is that it would also require a RefCell most of the time. So the whole thing would be filled with Rc<RefCell<T>>. With the required .borrow_mut(). It would both do a pain to do and undo.
And of course I want to undo it, because RC is a shitty GC.
I almost ignored that link because most of the opinions I’ve seen from Sweeney have been self-serving and/or misleading, but it turns out he raises some good points in that slide deck. It gets relevant to this discussion around page 27: Reliability. Thanks for sharing it.
Can you explain what you mean by “the cool kids”?