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Last active December 5, 2024 22:22
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Orthodox C++

Orthodox C++

What is Orthodox C++?

Orthodox C++ (sometimes referred as C+) is minimal subset of C++ that improves C, but avoids all unnecessary things from so called Modern C++. It's exactly opposite of what Modern C++ suppose to be.

Why not Modern C++?

Back in late 1990 we were also modern-at-the-time C++ hipsters, and we used latest features. We told everyone also they should use those features too. Over time we learned it's unnecesary to use some language features just because they are there, or features we used proved to be bad (like RTTI, exceptions, and streams), or it backfired by unnecessary code complexity. If you think this is nonsense, just wait few more years and you'll hate Modern C++ too ("Why I don't spend time with Modern C++ anymore" archived LinkedIn article).

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Why use Orthodox C++?

Code base written with Orthodox C++ limitations will be easer to understand, simpler, and it will build with older compilers. Projects written in Orthodox C++ subset will be more acceptable by other C++ projects because subset used by Orthodox C++ is unlikely to violate adopter's C++ subset preferences.

Hello World in Orthodox C++

#include <stdio.h>

int main()
{
    printf("hello, world\n");
    return 0;
}

What should I use?

  • C-like C++ is good start, if code doesn't require more complexity don't add unnecessary C++ complexities. In general case code should be readable to anyone who is familiar with C language.
  • Don't do this, the end of "design rationale" in Orthodox C++ should be immedately after "Quite simple, and it is usable. EOF".
  • Don't use exceptions.

Exception handling is the only C++ language feature which requires significant support from a complex runtime system, and it's the only C++ feature that has a runtime cost even if you don't use it – sometimes as additional hidden code at every object construction, destruction, and try block entry/exit, and always by limiting what the compiler's optimizer can do, often quite significantly. Yet C++ exception specifications are not enforced at compile time anyway, so you don't even get to know that you didn't forget to handle some error case! And on a stylistic note, the exception style of error handling doesn't mesh very well with the C style of error return codes, which causes a real schism in programming styles because a great deal of C++ code must invariably call down into underlying C libraries.

  • Don't use RTTI.
  • Don't use C++ runtime wrapper for C runtime includes (<cstdio>, <cmath>, etc.), use C runtime instead (<stdio.h>, <math.h>, etc.)
  • Don't use stream (<iostream>, <stringstream>, etc.), use printf style functions instead.
  • Don't use anything from STL that allocates memory, unless you don't care about memory management. See CppCon 2015: Andrei Alexandrescu "std::allocator Is to Allocation what std::vector Is to Vexation" talk, and Why many AAA gamedev studios opt out of the STL thread for more info.
  • Don't use metaprogramming excessively for academic masturbation. Use it in moderation, only where necessary, and where it reduces code complexity.
  • Wary of any features introduced in current standard C++, ideally wait for improvements of those feature in next iteration of standard. Example constexpr from C++11 became usable in C++14 (per Jason Turner cppbestpractices.com curator)

Is it safe to use any of Modern C++ features yet?

Due to lag of adoption of C++ standard by compilers, OS distributions, etc. it's usually not possible to start using new useful language features immediately. General guideline is: if current year is C++year+5 then it's safe to start selectively using C++year's features. For example, if standard is C++11, and current year >= 2016 then it's probably safe. If standard required to compile your code is C++17 and year is 2016 then obviously you're practicing "Resume Driven Development" methodology. If you're doing this for open source project, then you're not creating something others can use.

UPDATE As of January 14th 2022, Orthodox C++ committee approved use of C++17.

Any other similar ideas?

Code examples

@trcrsired
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trcrsired commented Dec 29, 2023

We're discussing the practical realities of the real world here, not delving into idealistic notions of socialism or communism.

The truth is, decisions made within WG21 predominantly cater to the interests of large international corporations. If these corporations have a plethora of issues to contend with, such as exceptions for bad_alloc or an overreliance on object-oriented programming, meaningful change becomes unlikely.

Should WG21 cease to serve the interests of these corporations, it's plausible that the organization would dissolve, or its leader might be strategically removed to safeguard those interests. This aligns with the principles of historical materialism. Much like World War II would have occurred without Hitler, the functioning of the US empire remains consistent regardless of whether Donald Trump or Joe Biden assumes the presidency.

In essence, WG21 has become an arena dominated by these major corporations. For instance, while Google advocates for an ABI break, other corporations may resist. Our opinions and expressions carry minimal weight in this scenario.

You mentioned "historical reasons," and this is precisely one of them. What you and I may criticize about the language is inconsequential.

To begin with, they are unlikely to heed our concerns. They disregarded them 30 years ago, and the situation remains unchanged. Had they been receptive, issues like permitting HP to incorporate exception handling in the manner they did 30 years ago would have been avoided. Similarly, if they were attentive, freestanding would not have lacked ::std::addressof until C++23, as Nvidia desired. Even in C++26, std::array remains absent in the freestanding context. The addition of features like std::filesystem, marred by dual error reporting mechanisms, stands as another testament to their lack of heedfulness.

Bjarne himself is clearly a big fan of bourgeois democracy and believes democracy fixes everything. While in reality, it is just another kind of dictatorship.

@trcrsired
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trcrsired commented Dec 30, 2023

I actually believe that C++ is communist. C++ is corner stone of Linux community, and everyone knows supporters of the free software movement are communist. It may as well be renamed to Communist++.

Don't let me even get started on JavaScript...

Free software has nothing to do with communism.

Whatever, C++'s history is always big corporation controlled. It is a fact and nobody should deny. If you look at how they vote in ISO, only big companies are allowed to vote. And companies like IBM had a long history of pushing C++ to support many legacy nonsenses, like EBCDIC execution charset.
If no one funds the WG21, it would just collapse.

The feature we as individual programmers need do not align with big corporations.

@aerosayan
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@bkaradzic hi,

After using Orthodox C++ standard for a few years, I can say the rule to allow new C++ features should probably be reworded in a different way.

  • "Due to lag of adoption of C++ standard by compilers, OS distributions, etc. it's usually not possible to start using new useful language features immediately. General guideline is: if current year is C++year+5 then it's safe to start selectively using C++year's features." - Orthodox C++

I don't think this rule is strict enough.
My reasoning is, in the statement you mainly provide a safety clause for ensuring people don't use unstable features.
While that is good, I don't think that's as specific as it should be.
Mainly because the problem of using modern features only bare their face after a few years of overusing them in your codebase.

For example:

  • Lambdas from your example, destroy compilation speed, and increase memory consumption of supporting tools like LSPs (clangd specifically).
  • Similarly constexpr functions also slow compilation, and severely increase memory consumption for LSPs.
  • Templates are also problematic, but we can use extern templates to make them usable, while still remaining fast to compile.

As I've observed, everything in modern C++ over-complicates the language, and slows down compilation.

All in all, if one allows modern C++ features without warning about the potential dangers of those features, and/or how to safely use them, then, I don't think it is Orthodox anymore, as they would need to depend on new standards (--std=c++11 --std=c++14 etc), and anyone could use bad modern features like std::ranges and think they're being safe.

Thanks.

@GabrielRavier
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@aerosayan What would you suggest doing, then ? Stay on C++98 ? It seems quite obvious that most of the things you are complaining about are just as present there, along with bigger footguns that the more recent standards have actually managed to remove over the years.

@aerosayan
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@GabrielRavier , I think most things that were included after C++11, are a mistake.

C++11 seems to be good enough for most things.

Though I should point out, that my aversion to modern features is due to unintended side effects, and not for the language version.

For example:

  • Almost all C++ devs heavily promote smart pointers, as they're supposed to be safe.
  • However, almost no one mentions that std::shared_ptr uses atomic locks and atomic addition internally for reference counting, so for critical software engineering, like scientific code development in my case, std::shared_ptr are harmful, as they'll degrade performance, but it will be extremely difficult, or even impossible, for us to find the cause of it.

If a team knows what is best for them, they can use whichever feature they want.

@DBJDBJ
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DBJDBJ commented Mar 4, 2024

GCC and clang should introduce new switch: /orthodox

@GabrielRavier
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GCC and clang should introduce new switch: /orthodox

@DBJDBJ what would the flag do ?

@amlel-el-mahrouss
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This should be the default way of doing C++
Feature creep is never good.

@DBJDBJ
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DBJDBJ commented Jun 29, 2024

@GabrielRavier

GCC and clang should introduce new switch: /orthodox

@DBJDBJ what would the flag do?

Enforce "all" the "rules" discussed here. The very first post on this page explains it. I would also add: bar std::

@meemknight
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Yo, hopping in the discussion, my style is that I just use std::vector and string and things like that. I think that using them is very nice and they don't really have many problems for 99% of use cases, writing them is horrible tho, so I would never write them. So basically I write C with methods, operation overloading, vectors, lambdas, std::file_system and one time a year templates 😂. I also never use destructors.

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