C++26: The Oxford Variadic Comma
sandordargo.comOf course since the old syntax is merely deprecated and not removed, going forward you now have to know the old, bad form and the new, good form in order to read code. Backwards compatibility is a strength but also a one-way complexity ratchet.
At least they managed to kill `auto_ptr`.
If two template spellings trip you up, C++ is not your biggest problem. The joke is that each 'cleanup' sands off a tiny rough edge while the commitee leaves the old strata in place, so the language keeps accreting aliases and exceptions instead of dropping dead weight.
PyCuda 2024, used fairly often in certain industries, still contains `auto_ptr` ;-;
I used to slay with this in code golfing competitions from TopCoder, where you had to implement a function to solve a particular problem, thanks to C pointer maths and the gcc generally putting function arguments in order in the stack.
Turns out, these two are equivalent in practice (but UB in the C++ standard):
double solve(double a, double b, double c, double d) {
return a + b + c + d;
}
double solve(double a ...) {
return a + 1[&a] + 2[&a] + 3[&a];
}> Turns out, these two are equivalent in practice
Not in the x86-64 SysV ABI they aren’t. The arguments will be passed in registers (yes, even the variadic ones), so how your compiler will interpret 1[&a] is anybody’s guess. (For me, x86_64-unknown-linux-gnu-g++ -O2 yields, essentially, return a+a+a+a; which is certainly an interpretation. I’m also getting strange results from i686-unknown-linux-gnu-g++ -O2, but my x87 assembly is rusty enough that I don’t really get what’s going on there.)
The cast in the invocation can be macro-ed away. And the best thing is, the actual stack layout and data movement/shuffling is pretty much identical to the approach with <stdargs.h>, and with no UB or compiler intrinsics.double solve(double a[]) { return 0[a] + 1[a] + 2[a] + 3[a]; } solve((double[]){1, 2, 3, 4});That's a compound literal, not a cast.
K&R syntax is -1 char, if you are in C:
double solve(double a,double b,double c,double d){return a+b+c+d;} double solve(double a...){return a+1[&a]+2[&a]+3[&a];} double solve(a,b,c,d)double a,c,b,d;{return a+b+c+d;}
Clarity and Elegance of Syntax > Backwards compatibility.
In my opinion anyway. C++ feels so bloated these days.
This seems pretty good to me just on the level of trying to read C as someone using C++. Parameter packs and variadic templates are easily the most confusing syntax in C++ and cleaning it up is... very welcome
Hats off for using "..." in your comment immediately after a valid identifier word and with no comma in between, given the topic of the article.
Hats off for noticing. Not to be taken for granted in an increasingly skimming-oriented world
I'm far from C++ but reading this article confused be, from the form to the impact to the dead link https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p12...
I guess that's a preview how C++ require a lifelong commitment.
C++ seems to be constantly getting complicated. If the major version were to change, there wouldn't be any need for backward compatibility with the existing code, and it would have been okay to delete that syntax while creating an automatic formatter.
Are you suggesting we move to C++++?
It's already there. It's called C#
Well, C# also has its quirks already. Like the crippled finalizers which are never to be used. If the IDisposable interface had been correctly designed, finalizers could become be the "public void Dispose(void)". Or the manual passing of Task in case of async methods, which is... kinda smelly.
It's possible you didn't realise, but C# is sometimes said to be named that way because # is the symbol you get if you draw ++ small and then on the line below ++ again. Hence C++++
All languages have some spikier edges, there are no languages I know where I think "Well, even if we could start over I have no idea how to improve this". What's notable about C++ is just how rich that "could do better" seam is, so very many of their defaults are wrong, so many of their keywords are the wrong word, so many of their standard library features are allowed, sometimes even mandated to be crap.
I don’t know if that’s true or not, but while the thought never crossed my mind before your comment, it’s now canon in my mind. Yes, C# is spelled C++++ with a ligature.
I think you meant to get that to the original poster, who seems to imply C# is the flawless, bestest incarnation of C\+\+(\+\+)+.
Personally I like C+. Picking the nice parts of C++, but skipping all the nonsense. I just wish C++ hadn't deliberately screwed up designated initializers with mandatory ordering. The C version of it that allows out-of-order assignments is clearly superior.
Didn't you read the article? That form is deprecated. The recommended one is C,++,++
learned something new. thanks for the article.
Yes, but no. I learned C++ in '90s when it was C with classes and some other noise added by Stroustrup. During the some 25 years that followed it had became a mess that's insanely hard to work with. I'm not going back to this language. I prefer plain C or Rust, leaning towards Rust when I fully comprehend the lifetime and borrow checker. Or when I have the luxury of having a GCed runtime, then the .NET with its easiest C# language with wonderful abundance of great libraries is the best choice. Nobody was ever fired for using .NET (for right purposes).
C++ got too complicated after C++23 I went back to C.
You can always restrict yourself to a subset of C++ that takes advantage of RAII (resource handling is extremely painful in C), and get performance benefits like move semantics, without the insanely complex stuff.
I love C, but C++ has worthwhile advantages even if you heavily restrict which features you use.
No offense intended to your perspective, but I do find it a little amusing that C++23, which was generally considered a disappointingly small update due to COVID complications, was the breaking point in complexity.
C is the new vinyl.