On Mon, 24 Mar 2025 at 09:36, Marcin Jaczewski wrote:

> pon., 24 mar 2025 o 10:13 Jonathan Wakely via Std-Proposals
> <std-proposals_at_[hidden]> napisał(a):
> > Yes, it seems appropriate as an attribute to me (but then I think the
> rule that attributes must be ignorable and can't change semantics is silly
> anyway).
>
> But for me it is right, as enforcing can be done by "clang format"
> when you push changes to a public repo.
> Or by other tools like PVS-Studio, or by only the developer of header
> library (if attributes affect self use in header) and his compiler,
> all user can use older compilers that are not aware of the attribute
> but still indirectly benefit from it.
>
>
Which means we can't ever standardize attributes for e.g.
[[gnu::always_inline]] or [[gnu::packed]] or [[clang::musttail]] or
[[no_unique_address]] (oh whoops, we did, and we come up with contorted
explanations for why it isn't *really* changing semantics and ignoring it
is fine), or alignas (oh right, it's defined as part of the attribute
grammar but is actually a keyword, because we couldn't add it as an
attribute due to the ignorable rule).

Attributes are precisely the right tool for extending the semantics in
particular places without having to introduce new keywords every time.