sorry, I can't take something that argues for "printf" in favour of anything else seriously.

> sorry, I can't take something that argues for "printf" in favour of anything else seriously.

I think you're arguing from a position of willful ignorance. The article is clear on how it lauds C++'s std::printnl, not printf.

http://en.cppreference.com/w/cpp/io/println.html

Here's what the article argues:

> With std::format, C++ has gained a modern, powerful, and safe formatting system that ends the classic, error‑prone printf mechanisms. std::format is not merely convenient but fully type‑safe: the compiler checks that placeholders and data types match.

Solid remark, and the consensus on how std::printnl and std::format are an important improvement over std::cout or C's printf.

I was referring to the Orthodox C++ article linked by parent. Of course format is an improvement on both printf and iostream.

I'll bite. printf might be unsafe in terms of typing, in theory, but it's explicit and readable (with some caveats such as "PRIi32"). The actual chance of errors happening is very low in practice, because format strings are static in all practical (sane) uses so testing a single codepath will usually detect any programmer errors -- which are already very rare with some practice. On top of that, most compilers validate format strings. printf compiles, links, and runs comparatively quickly and has small memory footprint. It is stateless so you're always getting the expected results.

Compare to <iostream>, which is stateful and slow.

There's also std::format which might be safe and flexible and have some of the advantages of printf. But I can't use it at any of the places I'm working since it's C++20. It probably also uses a lot of template and constexpr madness, so I assume it's going to be leading to longer compilation times and hard to debug problems.

The biggest issue with printf is that it is not extensible to user types.

I also find it unreadable; beyond the trivial I always need to refer to the manual for the correct format string. In practice I tend to always put a placeholder and let clangd correct me with a fix-it.

Except that often clangd gives up (when inside a template for example), and in a few cases I have even seen GCC fail to correctly check the format string and fail at runtime (don't remember the exact scenario).

Speed is not an issue, any form of formatting and I/O is going to be too slow for the fast path and will be relegated to a background thread anyway.

Debugging and complexity has not ben an issue with std::format so far (our migration from printf based logging has been very smooth). I will concede that I do also worry about the compile time cost.

I my experience you absolutely must have type checking for anything that prints, because eventually some never previously triggered log/assertion statement is hit, attempts to print, and has an incorrect format string.

I would not use iostreams, but neither would I use printf.

At the very least if you can't use std::format, wrap your printf in a macro that parses the format string using a constexpr function, and verifies it matches the arguments.

_Any_ code that was never previously exercised could be wrong. printf() calls are typically typechecked. If you write wrappers you can also have the compiler type check them, at least with GCC. printf() code is quite low risk. That's not to say I've never passed the wrong arguments. It has happened, but a very low number of times. There is much more risky code.

So such a strong "at the very least" is misapplied. All this template crap, I've done it before. All but the thinnest template abstraction layers typically end up in the garbage can after trying to use them for anything serious.

Error Log/assertions prints are by are the most likely code to have not been run prior. Some compilers type check printf, but not all.

I largely avoided iostream in favor of printf-like logging apis, but std::format changed my mind. The only hazard I've found with it is what happens when you statically link the std library. It brings in a lot of currency and localization nonsense and bloats the binary. I'm hoping for a compiler switch to fix that in the future. libfmt, which std::format is based on, doesn't have this problem.

The article argues that modern C++ has type-checked string formatting, so it does not argue for (unchecked) `printf()`, right?

"The article" is ambiguous. The one this HN post is about does not argue for it, at all. But the one in the comment above directly says,

> Don’t use stream (<iostream>, <stringstream>, etc.), use printf style functions instead.

and has a code example of what they argue 'Orthodox C++' should be, which uses printf.

I'm all for a more sensible or understandable C++, but not at the expense of losing safety. In fact I would prefer the other way: I still feel incredibly saddened that Sean Baxter's Circle proposal for Safe C++ is not where the language is heading. That, plus some deep rethinking and trimming of some of the worst edge behaviours, and a neater standard library, would be incredible.

I was indeed referring to the 'Orthodox C++ article'.

C++20 inverts the traditional relationship between the core language and metaprogramming, which arguably makes it new language in some ways. Instead of being a quirky afterthought, it has become the preferred way to interact with code. There is a point of friction in that the standard library doesn’t (and can’t) fully reflect this change.

Metaprogramming style in C++20 only has a loose relationship to previous versions. It is now concise and highly maintainable. You can do metaprogramming in the old painful and verbose way and it will work but you can largely dispense with that.

It took me a bit to develop the intuitions for idiomatic C++20 because it is significantly different as a language, but once I did there is no way I could go back. The degree of expressiveness and safety it provides is a large leap forward.

Most C++ programmers should probably approach it like a new language with familiar syntax rather than as an incremental update to the standard. You really do need to hold it differently.

I only which concepts were easier, those of use that don't use C++ daily have to look the expression syntax all the time, much better than the old ways I guess.

As someone that has only dabbled in C++ over the past 10 years or so, it feels like each new release has this messaging of “you have to think of it as a totally new language”. It makes C++ very unapproachable.

It isn’t each release but there are three distinct “generations” of C++ spanning several decades where the style of idiomatic code fundamentally changed to qualitatively improve expressiveness and safety. You have legacy, modern (starting with C++11), and then whatever C++20 is (postmodern?).

This is happening to many older languages because modern software has more intrinsic complexity and requires more rigor than when those languages were first designed. The languages need to evolve to effectively address those needs or they risk being replaced by languages that do.

I’ve been writing roughly the same type of software for decades. What would have been considered state-of-the-art in the 1990s would be a trivial toy implementation today. The languages have to keep pace with the increasing expectations for software to make it easier to deliver reliably.

As someone that has been using C++ extensively for the last 25 years, each release has felt as an incremental improvement. Yes, there are big chunks in each release that are harder to learn, but usually a team can introduce them at their own pace.

The fact that C++ is a very large and complex language and that makes it unapproachable is undeniable though, but I don't think the new releases make it significantly worse. If anything, I think that a some of the new stuff does ease the on-ramp a bit.

C++ can be written as the optimal industrial language it is. Simple core concepts year after year. Minimal adaptation.

The key thing to understand you are still using C with sugar on top. So you need to understand how the language concepts map to the hardware concepts. So it’s much more relevant to understand pointer arithmetic, the difference between stack and heap allocations and so on, rather what the most recent language standard changes.

You can write the same type of C++ for decades. It’s not going to stop compiling. As long as it compiles on your language standard (C++17 is fine I think unless you miss something specific) you are off to the races. And you can write C++17 for the next two decades if you want.

> Metaprogramming style in C++20 only has a loose relationship to previous versions. It is now concise and highly maintainable. You can do metaprogramming in the old painful and verbose way and it will work but you can largely dispense with that.

This was my takeaway as well when I revisited it a few years ago. It's a very different, and IMO vastly improved, language compared to when I first used it decades ago.

Wait until people see how reflection on c++26 further pushes the metaprogramming paradigm. I'm more hopeful for reflection than I have been for any other c++ feature which has landed in the last decade (concepts, modules, coroutines, etc).

If you're going to go through the effort of learning a new language, it makes sense to consider another language altogether, one without 30 years of accumulated cruft.

An advantage is that if you already know the older language then you don’t have to learn the new idioms up front to use it. You can take your time and still be productive. It isn’t why I would use it but it is a valid reason.

I have used many languages other than C++20 in production for the kind of software I write. I don’t have any legacy code to worry about and rarely use the standard library. The main thing that still makes it an excellent default choice, despite the fact that I dislike many things about the language, is that nothing else can match the combination of performance and expressiveness yet. Languages that can match the performance still require much more code, sometimes inelegant, to achieve an identical outcome. The metaprogramming ergonomics of C++20 are really good and allow you to avoid writing a lot of code, which is a major benefit.

As someone that had the option to choose between C and C++, coming from compiled BASIC and Object Pascal backgrounds, back in the early 1990's.

What makes C++ valueable is being a TypeScript for C, born in the same UNIX and Bell Labs farm (so to speak), allowing me to tap into the same ecosystem, while allowing me to enjoy the high level abstractions of programming languages like Smalltalk, Lisp, or even Haskell.

Thus I can program on MS-DOS limited with 640 KB, an ESP32, Arduino, a CUDA card, or a distributed system cluster with TB of memory, selecting which parts are more convinient for the specific application.

Naturally I would like in 2025 to be able to exercise such workflows with a compiled managed language instead of C++, however I keep being in the minority, thus language XYZ + C++ it is.

Does go count as managed, in your view? (Honest question - I don't know go well enough to have much of an opinion.)

I'd call managed C#, Java, Go, Pythhon, JS, etc. Something with GC e.g., managed memory

Yes, managed languages are all that have some form of automatic resource management, regardless of what shape it takes, or a more high language runtime.

Using Go as example, and the being in minority remark, you will remember the whole discussion about Go being a systems language or not, and how it was backpedaled to mean distributed systems, not low level OS systems programming.

Now, I remember when programming compilers, linkers, OS daemons/services, IoT devices, firmware was considered actual systems programming.

But since Go isn't bootstraped, TinyGo and TamaGo don't exist, that naturally isn't possible. /s

> C++ is valuable, because the existing tooling enables you to optimize the runtime peformance of a program

This is true for MANY other languages too, I don't see how this makes c++ different. With gdb its quite the opposite, handlig c++ types with gdb can be a nightmare and you either develop your own gdb glue code or write c-like c++.

> C++ is valuable becaus it's industry support guarantees code bases live for decades _without the need to modify them_ to latest standards.

In times of constant security updates (see the EU's CRA or equivalent standards in the US) you always gotta update your environment which often also means updating tooling etc. if you don't wanna start maintaining a super custom ecosystem.

I don't see this as a positive in general, there is bit rot and a software that is stuck in the past is generally not a good sign imo.

> C++ is valuable because the industry tooling allows you to verify large areas of the program behaviour at runtime (ASAN etc).

Sanitizers are not C++ exclusive too and with rust or C# you almost never need them for example. Yes C++ has extensive debugging tools but a big part of that is because the language has very few safeguards which naturally leads to a lot of crashes etc..

I think the idea of using only a small subset of C++ is interesting but it ignores the problem that many people have, you don't have the time to implement your own STL so you just use the STL. Ofc it gives me more control etc. but I'd argue most of the time writing orthodox c++ won't save time even in the long run, it will save you headaches and cursing about c++ being super complicated but in the end in modern environments you will just reinvent the wheel a lot and run into problems already solved by the STL.

> handlig c++ types with gdb can be a nightmare and you either develop your own gdb glue code or write c-like c++.

That's why better to use lldb and it's scripts.

> I think the idea of using only a small subset of C++ is interesting but it ignores the problem that many people have, you don't have the time to implement your own STL so you just use the STL.

Yeah, agree. It's just much easier to take a "framework" (or frameworks) where all the main problems solved: convenient parallelism mechanisms, scheduler, reactor, memory handling, etc. So it's turning out you kinda writing in your own ecosystem that's not really different from another language, just in C++ syntax.

orthodox C++ should be a subset of C++, I would really use it, like if there was a compiler flag

I can imagine it might be insanely faster to compile

Better language? Well, now mix those with C libraries thst you need and make them generate code as efficient as C++ (I would assume people use C++ for a performance advantage of some kind in many scenarios).