2025-06 LWG Motions 10–13 std::simd

[mattkretz]

Fixes #7947
Fixes cplusplus/papers#1531
Fixes #7948
Fixes cplusplus/papers#2134
Fixes: #7949
Fixes: cplusplus/papers#1383
Fixes: #7950
Fixes: cplusplus/papers#2321

[mattkretz]

Oh, I somehow messed up my tree and squashed motion 11 into a Fixup commit. Will fix.
edit: fixed

[mattkretz]

I need to call out 45ddf54, which is probably more than editorial. The paper forgot to add the simd-integral concept and that commit adds it. Needs an LWG issue, no?

[tkoeppe]

It if's obviously what was meant and its definition is obvious, I'd be perfectly happy to call that editorial. @jwakely?

[mattkretz]

simd-integral is a copy of simd-floating-point where floating_point gets replaced by integral. I certainly think it's obvious.

[jensmaurer]

Please add simd-integral as a separate non-fixup commit.

[mattkretz]

Ah, commit where the message doesn't start with 'Fixup' is meant as editorial non-fixup commit. Should I move all of them into another PR or a series of PRs?
Note that CI will fail without the simd-integral \defexposconcept unless I change \exposconcept{simd-integral} to \exposid.

[jensmaurer]

"fixup" commits will be squashed by @tkoeppe when he merges all the pull requests, so don't appear in the history. They are intended for stuff where the incoming paper wasn't transcribed properly (e.g. missed edit or so). We don't want to be reminded of these for all eternity.

In contrast, (editorial) fixes on top of papers that were not directly shown in the paper should be a "regular" commit (with section label at the start of the commit title etc.), but can (and, in this case, should) stay in the same pull request as the paper, because related to the paper. If someone does archeology, we can clearly see the add-on fixes that were not asked for in the paper.

In this particular case, since the CI fails without the fix, we do need the add-on commit in this very same pull request.

[jwakely]

It if's obviously what was meant and its definition is obvious, I'd be perfectly happy to call that editorial. @jwakely?

Yes, this seems like a straightforward consistency fix, the intent is clear.

[mattkretz]

I just noticed missing @ escapes and missing index entries for basic_mask::value_type/abi_type. Force pushed so that no fixup commit comes after editorial commits.