On Thu, 8 Aug 2024, Alejandro Colomar wrote:
> Hi Jens,
>
> On Thu, Aug 08, 2024 at 11:13:02AM GMT, Jens Gustedt wrote:
> > > but to maintain expectations, I think it would be better to do
> > > the same here.
> >
> > Just to compare, the recent additions in C23 typeof etc. only have the
> > parenthesized versions. So there would be precedent. And it really
> > eases transition
>
> Hmmm, interesting.
>
> The good part of reusing sizeof syntax is that I can reuse internal code
> for sizeof. But I'll check if I can change it easily to only support
> parens.
Since typeof produces a type, it's used in different syntactic contexts
from sizeof, so has different ambiguity issues, and requiring parentheses
with typeof is not relevant to sizeof/lengthof. I think lengthof should
follow sizeof. Make sure there's a testcase for lengthof applied to a
compound literal (the case that illustrates how, on parsing sizeof
(type-name), the compiler needs to see what comes after (type-name) to
determine whether it's actually sizeof applied to an expression (if '{'
follows) or to a type (otherwise)). (If you're following the sizeof
implementation closely enough, this should just work.)
--
Joseph S. Myers
josmy...@redhat.com
