Re: Proposal: Make use of C99 designated initialisers for nulls/values arrays

Jacob Champion <pchampion(at)pivotal(dot)io> writes:
> On Fri, Oct 4, 2019 at 7:51 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> I concur with Joe here. The reason why some of the existing
>> memset's use "false" is for symmetry with other places where we use
>> "memset(p, true, n)" to set an array of bools to all-true.

> Why introduce a macro at all for the universal zero initializer, if it
> seems to encourage the construction of other (incorrect) macros?

Well, the argument is that some people might think that if {0} is enough
to set all array elements to 0, then maybe {1} sets them all to ones
(as, indeed, one could argue would be a far better specification than
what the C committee actually wrote). Using a separate macro and then
discouraging direct use of the incomplete-initializer syntax should help
to avoid that error.

> IMO
> the use of {0} as an initializer is well understood in the C developer
> community, and I'm used to it showing up verbatim in code.

Yeah, if we were all 100% familiar with every sentence in the C standard,
we could argue like that. But we get lots of submissions from people
for whom C is not their main language. The fewer gotchas there are in
our agreed-on subset of C, the better.

regards, tom lane