#cpp29 — Public Fediverse posts

What can C++ developers expect from C++26 and beyond?

In this final part of the interview, Nicolai Josuttis and Jesper Pedersen talk about C++26, the feature freeze process, Contracts, the growing role of Reflection, and more.

Watch here: https://www.youtube.com/watch?v=2vsSJNWAiDw

#CPlusPlus #CPP #Cpp26 #Cpp29 #ModernCpp
https://www.youtube.com/watch?v=2vsSJNWAiDw

@mhoemmen mdspan feature request 😉:
Allow mdspan::operator[] with one argument less than rank.
Mandates/Constraints: The resulting range is contiguous in memory.
Returns: A span (of static extent, if possible).

Then I can use std::simd CTAD from range:
simd::basic_vec(B[k], simd::flag_aligned);

instead of:
simd::unchecked_load<simd::vec<T, N>>(&B[k, 0], &B[k, N-1], simd::flag_aligned);

The former is not only simpler but also safer.

#WG21 #cpp29

@meetingcpp

People need to be aware that the linked blog post is about a fictional world, which may or - more likely - may not become reality.

To have an impact, a fleshed out proposal with such changes to the C++ standard needs to show up in the committee to be discussed and voted on there. From what I can see so far, I'd like to see much better reasoning to support such a change.

If ever, the proposed syntax may become a thing in the next decade. Until then, there are other options to achive the desired behaviour.

#cpp29

Can we fix the following inconsistency in #CPlusPlus: https://compiler-explorer.com/z/qsYeTncE4? A conversion operator is sufficient to call wrapped function pointers. But it does not work for wrapped callable objects. And that's even though `wrapper` in the above example has the callable type in its associated namespaces (ADL). ADL was introduced to make operators work. I patched my #GCC to make it work and I like it.

#WG21 #cpp29 #cpp

@mkretz
"We violently agree" 😸

But P3802 will certainly have to wait until #cpp29 to become a portable C++ feature for apparent procedural reasons: it appeared *after* #cpp26 feature freeze, was never discussed in EWG, nor made it into a plenary vote. AFAICS, the mistake of #cpp0x will not be made again.

C++29 will be postponed to C++31

Otherwise we'll miss C++64, which has to integrate a fully functional C64 emulator in the standard library, called Commodore++64 (or C++64 for short)

#cpp #cpp29 #commodore64