If one is ready to switch languages, then the clear winner is rust over C++, and I say that as someone who avoided diving into Rust for years because it seemed completely overhyped and with too much cryptic syntax.
C still wins by far when writing libraries that will be used by lots of other people. Doesn't matter what language they are using, they will be able to add in a library written in C very easily. However, C++ or Rust libraries, even with appropriate bindings for the target language, users of the library will need to bring in an entirely new compiler tool chain that may or may not exist on the target architecture. But the C tool chain will exist for that architecture and be robust.
Availability of C++ tooling is much, much closer to availability of C tooling (often it's the same tool!) compared to Rust. Adopting Rust isn't the same category of conversion at all.
For new side projects, pick what you want to use of course. But for existing codebases and projects that aspire to have maximum impact, I recommend fully considering tradeoffs instead of thinking in terms of "clear winners".
> Availability of C++ tooling is much, much closer to availability of C tooling (often it's the same tool!) compared to Rust. Adopting Rust isn't the same category of conversion at all.
Which tooling? Just curious, asking entirely in good faith. My recollection is that the majority of tooling I was using with C++ worked with Rust - debuggers, profilers, and sanitizers being the main tools. Although I find that I use them much less frequently since I don't find debuggers as useful for the types of bugs I have these days, and sanitizers are only useful if you have unsafe, and profilers are cool but usually I just write benchmarks using a crate and then iterate from there.
And yet, even with that, Yann Collet credits Google's use of C++ for the compression library as a critical mistake that allowed him, an unknown, to gain traction with his own compression methods. Google later rewrote their library in C:
Even if the tool chain exists, it must be adopted, unless you can rely on binaries being available for your end users, which will never be the case for a library which is just starting our. And adding another dependency to your build process, especially one as complex and with as many breaking version changes as C++, is a lot of work to take on.
If you are going on proprietary tool chains... most of those are moving to llvm which rust is based on. In theory any proprietary toolchain based on llvm could provide rustc given incentives to do so.
If you are speaking to missing a rust compiler built on gcc, that seems to be an ongoing project with some momentum.
Realistically the most widely used architectures are now supported by rustc through llvm... x86, arm, riscv, and even to some extent xtensa now.
Power, arc, mips, sparc, and some others aren't too far away if someone cared enough.
If Linux can support Rust, I'd think that's a good sign most project can use Rust.
That's just the compilation toolchain. For better or worse, existing C projects have their whole workflows sitting on top of bespoke tools with the assumption that there is a C toolchain. And Rust projects assume cargo, etc. You're more or less doing a parallel rewrite in Rust to adopt Rust in an existing C project.
The Linux kernel already does extensive bespoke tooling and it's low level enough to skip cargo and such. It's rare to see that approach in Rust projects in the wild.
Are we just talking about portability then? Because "same category of conversion" seems fine - I would say that for 99.9999% of projects the difference in portability is non existent.
Basically all the libraries, IDEs, game engines, game console SDKs, HFT, HPC, OS SDKs, embedded OSes, High Integrity Computing certifications, and plenty more stuff deployed into production since C++ ARM [0] was published in 1990, 33 years ago.
This is nonsense. Rust is based off of LLVM, which is what Clang is based off of. Name one modern, actually used, non-archaic system that LLVM doesn't run on. Beyond that, Cargo and all associated tooling run pretty much everywhere. So I'm not sure what outdated trope you're on about here.
Exporting a stable C ABI/API in no way requires writing the implementation in C. See Android's NDK for a rather widely deployed example. All the APIs are C, yet none of the implementations are C. Same thing works great in Rust, too. You can trivially export C from a Rust implementation.
My comment acknowledged what you state, but then went on to point out that it requires adding a tool chain to compile Rust or C++, neither of which are trivia and which may not exist at all on the target architecture.
Rust in the kernel is a whole different beast than what most people think--no standard library, no cargo or external crates, some memory safety features removed. It's kind of just an alternative syntax.
Rust is by far not mature enough for serious development. Recent shenanigans with crablang are a strong sign of it going down the route of Java, i.e a corporate developed language with offshoots, which will end up with Rust being in the same crappy state.
>Except it's being used for serious development today
No, its being used for pet projects by people. Serious development = major companies using it in backends.
>So one of the most widely used applications programming languages in the world?
Because of CS programs, and legacy software written in java. Java has a community dedicated to pushing theoretical CS concepts into the language (much like Rust), while allowing things like a logging library to fetch code from anywhere on the internet and execute it, by default (which I would bet on would be the future of Rust given current trajectory)
Very few things in those companies are being written in Rust, and half of those projects chose Rust around ideological reasons rather than technical, with plenty of 'unsafe' thrown in for performance reasons
The fact that 'unsafe' even exists in Rust means it's no better than C with some macros.
Don't get me wrong, Rust has it's place, like all the other languages that came about for various reasons, but it's not going to gain wide adoption.
Future of programming consists of 2 languages - something like C that has a small instruction set for adopting to new hardware, and something that is very high level, higher than Python with LLM in the background. Everything in the middle is fodder.
But this isn't something the C++ language provides, which is hilarious.
C++ keeps C's crap array type as its native array type. You need to reach into the C++ standard library to get this awkward library type, std::array<type,N> and then finally you get an array type that remembers how big it is and has some basic features like swap.
I'm kind of on board with this, but the problem is that it's 30 years of rotten wood. Rust started from a more secure foundation and has put a lot of effort into stabilising even the trickier ground - whereas in C++ it's too often "Yeah, we don't think about it too hard, when there are strong winds I don't go up into the top floor, the creaking is very loud, I'd rather just never find out".
Example, Rust 1.0 had std::mem::uninitialized::<T>() which gives a T but it's obviously uninitialized. It's marked "unsafe" of course, but is that enough? Turns out they later realised that no, it's strictly never OK to do this, so the unsafe label was insufficiently cautious. Today std::mem::uninitialized is deprecated, Rust never removes stuff from the standard library, but you should not use this library call.
The type MaybeUninit<T> is the fix. Since MaybeUninit<T> might not be initialized, it's OK if it's not initialized, and since it might be T, it's OK for it to occupy the same amount of space as T. So, then we can initialize this memory, and tell the compiler it's initialized now, it's a T not a MaybeUninit<T>.
Can you guess how that works? It's pretty clever, and C++ could do almost the same trick, but it never has and my guess is it never will. If you don't know and are wondering, check that type definition carefully - MaybeUninit<T> is a union
For contrast, in his safety talk Bjarne Stroustrup just says as if it's obviously true, that it's safe to have uninitialized char arrays in C++. And his rationale sounds exactly like how std::mem::uninitialized happened - any possible value of a byte is a valid byte, so that's good enough, right? Nope, ask compiler engineers, there were plenty in the room when Bjarne said that, but he didn't ask them.
I believe conventionally they're called the Rust Evangelism Strike Force.
And it's true that the rotten wood was better than nothing. Nobody is suggesting that NT or Linux should somehow have been developed in Rust in the 1990s. But likewise we shouldn't resist renewal in newer, better materials.
That applies to compiler internals too. Plenty of trouble down there for C++, it's just that C++ programmers can more often be sent away by assuring them that what they did was UB and so LLVM is entitled to miscompile it whereas the Rust people keep arriving with the receipts, in the form of LLVM IR that is lowered to machine code which makes no sense
It's a standard library feature, rather than a language feature.
And you might say, "Who cares? Even freestanding has the standard library". Nope, std::array wasn't added to freestanding. You can dig into the messy details for yourself if you want, but suffice to say your freestanding C++ doesn't have std::array
So the C++ language has "arrays" but they're garbage, and if you point out that the arrays are garbage you're told to use this library feature, which may not be available.
The only valid complaint about std::array is that it's awkward to declare and takes more characters to type. It is, otherwise, vastly superior in every other way.
That doesn't make them garbage. That makes them annoying.
I feel like I already explained it's not even part of the language itself, it's a library feature, you aren't given this feature without the rest of the hosted C++ standard library.
Which is fine if you write Windows desktop apps, but this is an array type, unlike a GUI widget, or an XML parser, it seems like I'd probably want an array type for this $1 per unit micro controller I'm writing firmware for. In Rust the nice array type works just fine, it's a proper first class type, it knows how big it is, mutable arrays coerce into a slice I can sort (only unstably, but hey, we're embedded firmware let's not get fancy), I can iterate over it properly... in C++ only the crappy C-style array is available unless I can butcher the std::array so that it works outside the hosted library. Ugh.
You do not have to butcher. Standalone allocation free implementations are available if you are so in need.
But I see that you bring Rust in here. If that's your cup of tea then use it. No need to spill venom. Personally if I am dealing with $1 micros I very much prefer C with some selected libs for embedded. Do not really have problems with it for such small tasks.
I have never perceived it as a problem. I do not think it really slows my programming. Personally I am the guy who would prefer function() vs fn() but without going into extremes of Java culture. Besides you can always alias it to whatever you want if your fingers are so sensitive.
For me the issue is that using C++ brings every single feature in with it. It's very easy to hire developers and they know the entirety of the C language, but using C++ has every feature you could ever want and multiple ways of achieving the same thing.
It makes writing (and hiring) a low-level project in C++ a much more complex task. It may have benefits, it may not. But C++ is so huge that it's difficult to judge whether it would offer an advantage.
And then there's the minefield of tooling in embedded development...
Knowing every feature of C means they have to learn custom patterns on top of the C to make things work, and that almost always means horrific unhygienic macros.
These are dependent types which C++ does not have at all. The C support is fairly weak though... But most programming language people I know agree that dependent types are they way to guard against overflow with minimal overhead. So hope we can evolve C in this direction.
the obvious answer is that one does not want some things that C++ entails, three examples:
- name mangling
- larger gap between source code and ISA
- impedance mismatch when working with C APIs
that being said, some do not want more macros either
C still wins by far when writing libraries that will be used by lots of other people. Doesn't matter what language they are using, they will be able to add in a library written in C very easily. However, C++ or Rust libraries, even with appropriate bindings for the target language, users of the library will need to bring in an entirely new compiler tool chain that may or may not exist on the target architecture. But the C tool chain will exist for that architecture and be robust.