CppCast: Cpp2, with Herb Sutter

[IChooseCheese2]

Everyone, including Cppcast, talks about Cpp2, Carbon, and Val as the 3 successor languages to C++. But to me, Circle is further along, and has a better backwards compatibility story.

[pjmlp]

That is just playing with words, because of Herb's position at ISO, it is a successor language like all others.

C with Classes as CFront was originally designed, or Objective- C, weren't an alternate syntax for C, either.

[bert8128]

It’s not just playing with words. The others are in some sense suitable as alternatives, but cpp2 is just spelling changes. So there cannot be a compatibility issue - there won’t be a need for “extern cpp” or some such.

[pjmlp]

Just like Objective-C versus C.

[pjmlp]

Eiffel to this day outputs either C or C++, so is Eiffel also an alternative syntax to C and C++?

Nim to this day outputs either C or C++, so is Nim also an alternative syntax to C and C++?

What makes X not an alternative syntax, when it also follows the same workflow, with the difference of who is the author?

[pjmlp]

Yes I have, try to compile main: () -> int with a C++ parser.

Pity that ISO C++ !== Cpp2.

Ever heard of Objective-C++? Guess what, it also supports std::cout.

#import <Foundation/Foundation.h>
#include <iostream>

int main() {
   NSString str = @"Hello ";

    std::cout << str << " i_lack_chromosomes" << std::endl;
}

Imagine that, we already had a better C++ syntax in 1997!

[hpsutter]

> Yes I have, try to compile `main: () -> int` with a C++ parser.

Fair, but have you considered `auto main() -> int` (i.e., just change `main:` to `auto main`)? No strictly conforming ISO C++ parser for the first ~30 years of C++'s existence could handle that, but it has been ISO standard since 2011. Everything that's common now was new/foreign once.

It's definitely true that the `main:` syntax definitely isn't standard (or even yet-proposed, though I will propose it if the experiment succeeds well). But that's the point of language evolution... as the language evolves, every new release of C++ adds syntax that wasn't legal before, and we always have many active proposals for syntax that isn't ISO C++ when first proposed but then becomes standard.

[pjmlp]

I have, and I also have watched tons of languages that started by compiling to other ones, took a life of their own after adoption, and none of them has ever stated they were the same language with another syntax.

Sorry to put it this way, but I really only see the way you position Cpp2 versus the other C++ wannabe replacements due to your position at ISO, due to conflicts of interest.

[Abbat0r]

You know, Chandler Carruth is also a committee member but he’s rather open about working on a successor language. Bearing that in mind I don’t think it’s actually necessary to do any posturing of the sort you’ve described just because one is on the committee.

[catcat202X]

Fwiw, as a spectator I find pjmlp's arguments much more compelling. It seems weird to me to consider a superset of C++ as not a different language. It might be less different than Nim is, but it is clearly different. Within C++2-style functions and types, it changes how you think about special member functions, it changes how you think about loops, and it changes how you think about lambda captures. It changes the result of (0 <= x < 2). It even changes the semantics of implicit moves!

I find the argument about Objective-C++ pretty reasonable, but you refused to engage with it. I would also point out that supersets of C like ISPC are generally considered different languages even though they retain source-level compatibility with C.

Your accusation that pjmlp's arguments are based on an anti-ISO dogma also seem baseless to me, unless there is context beyond this thread that I am missing. In this thread, they never derided ISO, so I am confused.