[wish] Flexible array members in unions
Joseph Myers
joseph@codesourcery.com
Thu May 11 20:53:52 GMT 2023
On Thu, 11 May 2023, Kees Cook via Gcc wrote:
> On Thu, May 11, 2023 at 06:29:10PM +0200, Alejandro Colomar wrote:
> > On 5/11/23 18:07, Alejandro Colomar wrote:
> > [...]
> > > Would you allow flexible array members in unions? Is there any
> > > strong reason to disallow them?
>
> Yes please!! And alone in a struct, too.
>
> AFAICT, there is no mechanical/architectural reason to disallow them
> (especially since they _can_ be constructed with some fancy tricks,
> and they behave as expected.) My understanding is that it's disallowed
> due to an overly strict reading of the very terse language that created
> flexible arrays in C99.
Standard C has no such thing as a zero-size object or type, which would
lead to problems with a struct or union that only contains a flexible
array member there.
--
Joseph S. Myers
joseph@codesourcery.com
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