Re: Results of survey re. a new array size operator

On 2025-01-24, Alexis <flexibeast@gmail.com> wrote:

>
Hi all,
>
JeanHeyd Meneide, a Project Editor for WG14, has just posted the results
of a survey re. the preferred form of a new array size operator:
>
"There is a clear preference for a lowercase keyword, here, though it is
not by the biggest margin. One would imagine that with the way we keep
standardizing things since C89 (starting with _Keyword and then adding a
header with a macro) that C folks would be overwhelmingly in favor of
simply continuing that style. The graph here, however, tells a different
story: while there’s a large contingency that clearly hates having
_Keyword by itself, it’s not the _Keyword + stdkeyword.h macro that
comes out on top! It’s just having a plain lowercase keyword, instead."

The best way to have versioning for this in a C compiler is a
language dialect selection option.  Say that C27 (or whatever year)
adds an "arraysize" keyword.

- To use that keyword in the updated gcc, you use -std=c27.

- To compile programs written for C99, use -std=c99. Those
  programs can use arraysize as an identifier.

- To move those programs to C27, you fix all the uses of
  that identifier.

I don't see why we need _Keyword cruft with a header which provides
a macro alias, when compilers not only can have dialect selection
options but realistically cannot avoid doing so.

I hope the propsed array size keyword raises a constraint violation when
applied to a non-array. GCC had to develop a diagnostic for when sizeof
ptr is divided by sizeof ptr[0]!

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