Hi Thiago,

On 2026-02-09T21:43:52-0800, Thiago Macieira via Std-Proposals wrote:
> On Monday, 9 February 2026 16:38:26 Pacific Standard Time Barry Revzin wrote:
> > Moreover, override and final are... extremely ignorable. All they do is
> > request a diagnostic for otherwise well-formed code.
>
> "Diagnostic required" does mean it cannot be ignored: it must be handled and
> the diagnostic printed. An implementation is non-conformant if it eats the
> token then immediately forgets about it, unlike for attributes.

This is part of what makes attributes broken by being ignorable. Or at
least, depending on what you consider ignorable. [[reproducible]] is
very dangerous --and will eventually become even more dangerous-- by not
having mandatory diagnostics on misuse.

Or [[nodiscard]], FWIW, which you can't really trust, because some
diagnostics might not be generated at all. We need strict diagnostic
rules, even for ignorable attributes.


Have a lovely day!
Alex

>
> It would also not be the first case where you can only add a given keyword if
> it was already implied: inline, extern and auto (pre-C++11) come to mind, in
> some cases. You can add inline to constexpr function declarations or to
> definitions functions inside class bodies, but they already implicitly inline.
> You can add extern to the forward declaration of a function, but it does
> nothing because it's implied. You could add auto to declare that an automatic-
> storage variable had automatic storage, but it was implied (and it was also
> the only place where you could add it).
>
> --
> Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
> Principal Engineer - Intel Data Center - Platform & Sys. Eng.



> --
> Std-Proposals mailing list
> Std-Proposals_at_[hidden]
> https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals

-- 
<https://www.alejandro-colomar.es>