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Re: Bogus ifdef guard in sys/null.h



On Sat, Jul 17, 2010 at 08:20:45PM +0000, Valeriy E. Ushakov wrote:
> I read [#3] to mean that you shouldn't #undef only "identifiers that
> begin with an underscore and either an uppercase letter or another
> underscore" (the first item in the list in [#1]), and that it doesn't
> cover all items from the list.

Yes, that part doesn't apply. The only other part that talks about
#undef of macros is if they have functions as backing. E.g. isalpha().
So from my reading of the standard, it is simply unspecified.

Joerg


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