Rust doesn't have a runtime so it looks just like C in compiled form. c-bindgen even spits out a c header. I’m not sure what skipping C practically means even if you can argue there’s a philosophical skip happening.
You can't apply all of the hacks C programmers apply, like calling private methods, because Rust's internal ABI is different in some annoying spots.
Of course you shouldn't do that, but it's a problem rust-to-c conversion would solve.
Another reason I could think of is the desire to take something licensed in a way you don't like, written in Rust, for which you'd like to call into the private API in your production code, but don't want the legal obligations that come with modifying the source code to expose the methods the normal way.
I don't think either use case is worth the trouble, but there are theoretically some use cases where this makes sense.
It's also something I might expect someone who doesn't know much about Rust or FFIs outside of their own language might do. Not every language supports exporting methods to the C FFI, and if you're coming from one of those and looking to integrate Rust into your C you might think that translation is the only way to do it.
Most likely, it's a way rust haters can use rust code without feeling like the "other side" has won.
I'd like to write Rust, receive its safety benefits (esp borrow checker), compiler to equivalent C, and then use C's tooling on the result. Why use C's tooling?
In verification, C has piles of static analyzers, dynamic analyzers, test generators (eg KLEE), code generators (eg for parsing), a prover (Frama-C), and a certified compiler. If using a subset of these, C code can be made more secure than Rust code with more effort.
There's also many tools for debugging and maintenance made for C. I can also obfuscate by swapping out processor ISA's because C supports all of them. On the business end, they may be cheaper with lower watts.
I also have more skilled people I can hire or contract to do any of the above. One source estimated 7 million C/C++ developers worldwide. There's also a ton of books, online articles, and example code for anything we need. Rust is very strong in that last area for a new language but C/C++ will maintain an advantage, esp for low-level programming.
These are the reasons I'd use Rust if I wanted C or C++ for deployment. Likewise, I wish there was still a top-notch C++ to C compiler to get the same benefits I described with C's tooling.
Rust is much easier to learn due to C/C++ books all being paid (even cmake wants you to buy their book) whereas Rust documentation is free. I bet more and more people are choosing to learn Rust over C/C++ for this reason, and the number of C/C++ devs will be decreasing.
what a weird take to me... C has DECADES of high quality teaching material in form of books, university courses, plenty of which is freely available with a bit of searching.
And, if we discount the fact that "buying" a book is such a big hurdle, even more high quality academic text books and papers to boost; anything from embedded on the weirdest platforms, basic parsing, writing compilers, language design, high performance computing, teaching of algorithms, data structures, distributed systems, whatever!
edit: I even forgot to name operating system design plus game programming ; and of course accompanying libraries, compilers & build systems to cover all of those areas and use cases! edit2: networking, signal processing, automotive, learning about industry protocols and devices of any sort... if you explore computer science using C as your main language you are in the biggest candy store in the world with regards to what it is you want to learn about or do or implement...
> C has DECADES of high quality teaching material in form of books, university courses, plenty of which is freely available with a bit of searching.
Which means all that high quality teaching material is DECADES old. Rust development is centralised and therefore the docs are always up-to-date, unlike C/C++ which is a big big mess.
Being decades old does not make it out of date. Until a few years ago, the Linux kernel was written using C89. While it has switched to C11, the changes are fairly small such that a book on C89 is still useful. Many projects still write code against older C versions, and the C compiler supports specifying older C versions.
This is very different than Rust where every new version is abandonware after 6 weeks and the compiler does not let you specify that your code is from a specific version.
A long time ago, Victor Yodaiken told me the best way to learn C was the old, K&R book. The explanations, examples, and even pitfalls were all explained well. My code worked without much fuss. That's probably because C hasn't changed much.
I ended up switching to Python for job requirements after getting through half the book. If I re-learn C, I'll go back to it. If it were C++, that would be a totally, different story since they kept piling features on over time.
Oh my... Are you serious? I'm almost triggered by this. A book about algorithms or data structures from 20 years ago has nothing more to teach? 3D game engine design from 20 years ago has nothing more to teach? No point in looking at the source code of Quake, reading k&r, and Knuth's TAOCP Volume 1 was published in 1968 so it's obviously irrelevant garbage!
I could spurr into an essay of what kind of lack of understanding you just portrayed about the world, but I won't.... I won't...
> edit2: networking, signal processing, automotive, learning about industry protocols and devices of any sort...
I admit there is many great products that are written in C that aren’t going anywhere any time soon, notably SQLite, but there is no reason to write new software in C or C++.
I wrote a new daemon in C the other day. Plenty of people will continue to write software in C. Some will even write it in C++. There is nothing you can write that will convince the world to stop writing software in these languages. We went through this once with Java. We are going through it with Rust. We will go through it with Zig or whatever it is that people say everyone should adopt next instead of Rust and all else that came before it.
There's tools that can prove the absence of runtime errors in industrially-useful subsets of C. Frama-C, RV-Match, and Meta's Infer come to mind. That code is then usable in about anything because so much of it is written in or can call C. Until Rust has that combo, there's still a reason to use C.
Personally, I'd use both Rust and C with equivalent code. The Rust types and borrow checker give some extra assurance that C might not have. The C tooling gives extra assurance Rust doesn't have. Win, win. If I want, I can also do a certified compile or cross-compile of the Rust-equivalent, C code.
I do, and will, the industry does and will, for at least a few more decades. And I even enjoy doing so (with C; C++ is more forced upon me, but that'll be the case for some time to come)
> anything from embedded on the weirdest platforms, basic parsing, writing compilers, language design, high performance computing, teaching of algorithms, data structures, distributed systems, whatever
All that is language-agnostic and doesn’t necessarily have anything to do with C.
Yes, but there is material covering all of those aspects with implementations in C plus libraries plus ecosystem support! From teaching material to real world reference implementations to look at and modify and learn from.
And C maps so directly to so many concepts; it's easy to pick up any of those topics with C; and it being so loose makes it even perfect to explore many of those areas to begin with, since very quickly you're not fighting the language to let you do things.
The last I checked various stats (GitHub Language stats, TIOBE, etc.), Rust wasn't even in the top 10. I'm sure its adoption is increasing. However, other languages like Go seem to be doing much better. Neither will replace C++ or C anytime soon.
Compiling Rust to C doesn’t simplify interoperability. Either way you’ll be calling C functions. I assume compiling Rust to C is useful if you’re targeting some esoteric platform that Rust compiler doesn’t support.