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by rfgplk 3 days ago
One thing I've noticed about a lot of these "strict C" developers is that quite often they actually refuse to learn C++. One of the most common complaints of C developers regarding C++ is "it does things behind the scenes/performs magic", often with regards to operator overloading. When they refuse to actually look at the implementation (y'know you can check if an operator has been overloaded) AND they refuse to acknowledge that a huge chunk of "pure C" does HEAPS of magic behind the scenes (that the developer has no idea about) unless they've actually studied the spec in detail. Malloc and memory allocation methods are at least 10k+ lines of code for instance.
11 comments

I don't think "refusing to learn C++" is the right way to frame it. I want to use the language features that are actually useful to me, without being forced into a specific programming style. I can't speak for every "orthodox C++" programmer, but for me that means using exclusively plain-old-data structs, non-member functions, and "dumb" pointers. I have no issue with learning to use a C++ feature when it's directly useful to a problem I'm trying to solve.

As one example, I recently found templated lambdas useful in making animations.

https://www.youtube.com/watch?v=cw-h0dePYZM

Right. Use/Choose those features you are most knowledgeable/comfortable with. That is why C++ has such a smorgasbord of features and supports multiple paradigms. Over time, as one learns "better ways" (for a certain definition and one is convinced of it) of doing something change/modify as needed.

That is all there is to it.

I was programming in C++ before switching to C and I would say that C++ adds a huge amount of mental load compared to C. I think one can understand how much of a relieve it is to not worry about everything C++ does only after not using C++ for a quite a while.
Any time I go back to C from C++, it's only comfortable if I've got a C utility library that replaces most of std::

And that utility library (there are dozens of them) is just as subject to debate and issues as libstdc++

I am not going to implement my own C versions of 90% of the stuff std:: provides, sorry.

There is a difference between "needing a library" and "implement my own". One can just pick one. And even when implementing things yourself, one has to do this just once.
> y'know you can check if an operator has been overloaded

And there lies the problem with C++: to be sure, you have to check. C++ code can't be taken at face value -- the most innocuous-looking code could be a ticking bomb.

Just like any C function without looking into the translation unit, don't say you blindly believe on the function name.
Not really. C++ is on another level altogether: the code could be calling implicit conversion operators, the compiler could have instantiated some template code in an unforeseen way, and so on.

Years ago, I was really proficient in C++, but after a year of programming in C#, I realized that not once had the behavior of my code caught me off guard. In the following years, I only ran into quirky behavior a couple of times. I could finally program without the constant mental overhead of watching out for C++ pitfalls.

I suppose you're aware C# also has implicit conversion operators, operator overloading, reflection, aspect oriented programming, compiler plugins, interceptors.

Seems strange to talk down C++ while praising C#, which incidentally has been getting features to increase its use where Microsoft previously might have used C++ instead.

You catch pitfalls in any language the same way, using static analysis, which C authors introduced right in 1979, acknowledging the issues with language, which they decided to outsource to another tool, instead of improving the language.

A long tradition in computing.

Yes, C# is becoming more and more complex, but IMO C++ is still in a class of its own. Just compare how many different, sometimes competing ways there are to initialize variables in C++, each with its own subtleties.

I guess we'll have to agree to disagree here. And of course, even if C++'s user base seems to be shrinking, it still works well for some categories of programmers.

Even if it is shrinking, people leaving C++ aren't racing to go back to C, rather to languages with similar expressive type systems.

Swift, C#, Kotlin, Scala, Rust, Typescript, Python...

In D, we've introduced editions so that obsolete, problematic, or redundant features can be removed.
Finally happened! Thanks for the heads up.

Yeah C# is getting a bit unwidely.

My favorite was the regex engine that was implemented using C++ operator overloading. The author was very proud of it, but you could not tell what code was regex code and what code was math code.

I went to some lengths with D to discourage such abusive operating overloading practice.

Thank you. I don't even use D, but appreciate all efforts to socialize sane programming practices.
Thank you for the kind words! I recently did a presentation at Yale where I felt free to ridicule some insane practices, and how to do a better job.

Slides:

https://walterbright.com/ElegantD.pdf

But isn't this a problem with all code? Looking at a Rust function signature how can you be sure that it does what it says it does? Or python?
To the extent that one doesn't try to suppress compiler warnings & errors / actively break the language, you get what the compiler confirms is true about a function signature.

For Python, it's very little (nothing?). For Rust, you get more than most; lifetimes tell you whether it holds onto a pointer you give it.

See my reply to a similar objection: https://news.ycombinator.com/item?id=48520416
> C++ code can't be taken at face value -- the most innocuous-looking code could be a ticking bomb.

You can't take C code at face value either. The name of a method or type doesn't tell you what it does. It could longjmp for all you know.

See my reply to a similar objection: https://news.ycombinator.com/item?id=48520416
A lot of us are too busy solving problems. Learning about the latest language features, which we often won't be able to use anyway due to the trouble of moving a large dev environment to a newer standard, feels like academic masturbation.

C++ folks are very much into their language, and can't seem to understand that most folks don't want to dedicate significant amounts of mental resources purely to language details.

Moving to new C++ is a non event, change the compiler / flags and done. Using the new features requires some learning but not a big deal since you can figure out what you need from a summary and learn what is useful for your problem.

The problems of the code I'm writing far exceeds the complexity of the language. Your complaint about complexity fall flat to me, unless you are working on a trivial program you need to deal with things far more complex than any language.

It's really not. For us, changing compiler versions has noticeable effects throughout our codebase. I'm glad you don't have to deal with that though.
Like implementing the compilers used by C devs.
GCC was implemented in C and there are plenty of other C compilers written in C. GCC has been converted to C++ at some point, but large parts are still essentially C and I do not think the change to C++ was actually helpful (but others may disagree). In any case, the idea that one needs C++ to have C compilers is certainly simply wrong.
My original C compiler was implemented in C and then bootstrapped. Zortech C++ was implemented in Zortech C, and then bootstrapped.

D was implemented in "C with Classes" and then translated to D and bootstrapped. There isn't a line of C code in it.

Over time, we gradually replace the C-isms and C++isms and anachronisms in it to native D-isms.

Clang/LLVM with its more permissive licence sees _much_ wider use and is written purely in C++. PlayStation, automotive, platforms and runtimes like Chromium/V8, Android, etc. are all built with Clang.
Clang usage is a fraction of GCC usage.

Regards, an embedded dev.

A decade ago surely, in 2026 I doubt it.

With Android, iDevices, PlayStation, Switch, and everyone that had proprietary compilers down using downstream forks from clang, due to the more appealing license.

Who is left still using GCC, other than existing projects lacking a clang backend for a snowflake embed CPU?

In any case, if it is a modern GCC release past 2012, it was compiled with C++ as well.

How is this relevant? (also wider use for C I would doubt)
Naturally GCC was originally written in C, given its age, and the original GNU coding standards document.

With time, the GCC developers acknowledged the benefits of using C++ over C, and migrated the code.

GCC requires a C++ compiler to bootstrap since around 2012, and GNU coding standards has been updated to several languages beyond C, time to go up with times.

I think the fallacy of this argument is obvious.
Not really, given that GCC no longer compiles with a pure C compiler.

Unless of course, you don't have anything to do, and feel like bootstraping GCC 16, using a compiler chain all the way back to 2012 thereabouts.

All the foot guns in C are still in C++, and C++ adds a significant multiple more.
The regular table saw is still in the new workshop, and the new workshop adds a SawStop and another regular table saw.
Literally untrue. Two words: stronger typing.
Memory corruption magnets like iterator invalidation, std::string_view or std::span are on a whole different level than the footguns that were inherited from C. At least with C style raw pointers you know that you have to be careful when you see one, in C++ the unsafety is lurking in hidden places sprinkled all over the stdlib and comes in all shapes and forms.
Trust me, I know more C++ than most or all of my peers (working two jobs simultaneously), and I know a million ways that C++ features suck. Also standard library and containers. If you want I'll point out the ways in which std::deque, and even std::map, std::unordered_map, even std::vector (!) suck. IMO, just don't do it.
The standard library implements really do suck (in some cases), but this should be separated from C++ (the language). Even the standard splits the language grammar from the standard library cleanly.
You can't really separate the two, firstly because some parts of the standard library interact directly with the language's syntax (e.g. <initializer_list>), and secondly because the language standard dictates things about the behavior of the standard library that limit implementation options.

For example, the standard says that adding elements to an <unordered_map> is not allowed to invalidate references to keys or elements within the map. That makes it impossible for any standards-compliant C++ implementation to use a high-performance implementation in which keys and elements are stored contiguously in a flat array.

Your map example only concerns the standard library, not the language.
Its behavior is dictated by the language.

The context of this thread is that someone stated that the C++ standard library sucks, and someone replied to them saying that it's just some implementations that suck, but that's separate from the language. The point I'm trying to make, in response, is that it is about the language. It's not just "some" implementations - there is no implementation of the C++ standard library that doesn't have these inefficiencies, because the language's own standard requires them.

(This is tangential but - this is why I often say that C++ is not actually the most complex language in the world, it's just over-specified. If you took almost any popular programming language and wrote a document dictating the behavior of every single feature and library to the same level of detail, you would end up with a document similar in length or even longer than the C++ standard.)

In my reading, they didn't say it's due to bad implementations, though. They were trying to separate the standard into two parts, the one about the language syntax and semantics, and the one about the standard library. And I think this is a fair separation actually. But that doesn't make the core language any better ;-)
Which sucks... unless you really need reference stability.
std::vector has left the chat.
and even std::map, std::unordered_map, even std::vector (!) suck

It's really hard to take your comment serious because of generalization like this. Maybe they're not usable for your particular usecase but that doesn't mean they suck. Just like there's a 'million' ways that C++ sucks in your book, there's a reason there's millions of lines of code out there where these containers are valid usecases and hence work without issues whatsoever nor a need to replace them with something else.

std::map and std::unordered_map are just unbelievably shitty implementations. The former is a red-black tree, which in my entire programming career I have needed to reach for like... twice? It's just not the right container for almost any problem you have, yet it's the one that gets the short, sweet name. The latter is a bucket-based hashmap, which is about the worst kind of hashmap that can be built. On top of that, their APIs are also really annoying to use compared to, say, Python or Rust's implementation. At least C++20 finally added a simple contains method, but something like setdefault is just a chore to get implemented.
Not really apropos any of this but a vivid career memory for me is leaving a startup that was all in C++ and going to Arbor Networks, which was all C, and porting the STLport map to rbtree.c and making it our default container. No, I have no idea why I did that. Different times!
Pretty much the only collections I use are:

1. arrays

2. linked lists

3. hash tables

4. simple binary trees

They're not useable for anything serious, i.e. high throughput, low frequency, massively concurrent work. In other words, most of the things for which you shouldn't better have chosen a different language in the first place.

They're also unusable by the way because of ergonomic and software architecture factors, such as bad modularity, terrible compile times, unreadable error messages, unreadable symbol names...

Yes that is overgeneralizing a little bit but it's largely true.

The problem is typically not the containers themselves but all the other bad decisions that they push you to make in order to work around their "small issues".

The huge problem is that these containers can get you started quickly, i.e. leetcode type stuff and single threaded stuff, but at some point you'll realize your architecture ended up completely in the wrong place because of that.

If you haven't been thinking deeply about memory management and concurrency, you won't be able to understand, no offense meant. I've just fixed another subsystem that was completely overwhelmed, seeing 8x bandwidth gains already on a small testsystem, but the factor is basically unbounded when moving to bigger systems, when it's about contended vs uncontended.

> anything serious, i.e. high throughput, low frequency, massively concurrent work

Why is only 'high throughput, low frequency, massively concurrent work' considered 'serious'?

They're just clearly inferior in pretty much any situation.

The map stuff the other posters summed up well but even std::vector is dogshit with pretty much all implementations having inlined grow code in push_back, a not too great API and missed optimisations e.g. no trivial relocation when growing the vector / moving it and no useful APIs such as "grow but don't initialise"...

To be fair grow-but-don't-initialize is a pretty fundamental part of the API, the reserve() method.

But already the basic premise that you should push back without thinking is wrong. You will suffer reallocations and invalisations when you least expected them, and frankly you have to architect around that fact which is a terrible restriction. You can work around by pre reserving but at that point it's just a basic fixed heap allocated array but worse because the type gives you a weird look all the time, "I'll realloc as soon as you don't pay attention, harhar"!

You are free to make your own definition, what are your suggestions?

(Obviously I meant to say low latency, not low frequency)

That is a cop-out. You made the assertion, you define it.

What about these particular workloads (and the environments they're used in) make them 'serious' and why are other workloads 'lesser' and therefore the standard library 'suffices'? Why not use better containers for everything? Google, for instance, universally recommends Abseil.

Because if you don't need any of these, any slop implementation will do.
If you haven't been thinking deeply about memory management and concurrency, you won't be able to understand, no offense meant

I do think about that, when needed. My point is that these containers can be 'good enough' in places where it doesn't really matter, not that they're always the go-to thing. E.g. I really don't see any issue using a map as part of a configuration type of object which gets read from args or json and which only gets used once at application start.

Yes. When you don't have any specific requirements, any mediocre data structure will do.
c memory allocation functions can be implemented in 1000 lines or so. I've done it myself. Maybe more are needed to handle strange operating systems or architectures, as glib does.
> Malloc and memory allocation methods are at least 10k+ lines of code for instance.

Only the really big ones, e.g. here is Emscripten's allocator that focuses on small binary size and is implemented in about 1.5 kloc (ignoring comments and whitespace it's actually under 1 kloc), and that allocator is perfectly fine for most use cases (especially C code bases which typically don't have a high allocation frequency):

https://github.com/emscripten-core/emscripten/blob/main/syst...

...and Seb Aaltonen's offset allocator (used for allocating GPU buffers in his Vulkan API wrapper) has under 500 lines of code:

https://github.com/sebbbi/OffsetAllocator/blob/main/offsetAl...

Right tool for the job etc... big general-purpose allocators like jemalloc or mimalloc are usually a bandaid to somewhat salvage a failed memory management strategy.

If we accept the maximum that "any sufficiently advanced technology is indistinguishable from magic", then c++ is indeed magic. It's so advanced that one of the worlds foremost experts in the language(herb sutter) has determined that the language is too complex and we need a whole new language(confront) which is simpler and can be converted to c++.
C++ is actually obscenely complex, I don't deny that. Just mastering object lifetime rules is crazy difficult due to all the edge cases, but it comes with the territory.
> it comes with the territory

In the sense that C++ is complicated because it's C++, which is complicated? That's just a tautology. If you mean "the territory" in some other sense there's no reason to believe this.

“It’s so much magic! Now if you’ll excuse me, I have to go use my generic container library rewritten in 50 layers of preprocessor macros.”
C programmers aren't complaining about the "magic" being tens of thousands of lines of code. They're complaining about the magic including bizarre side effects that brazenly violate the principle of least astonishment.

In C++, you can overload the comma operator to do shit. I've seen it done. There's no reason to do it, and no reasonable person would ever expect it in a code base they're unfamiliar with. To find bug in that ultimately roots back to that implementation, you have to go eliminate every other whack-job possibility before it even occurs to you that maybe the weirdo who wrote this code chose to overload the comma operator.

I'm not going to argue with anyone who wants to use C++ in their own projects, you do you. But let's be real about what C programmers are complaining about. It's not line count. It's syntactic obfuscation. I don't just level this criticism at C++ either. Basically every major new language has its own byzantine syntactic constructs to some degree.