Fwd: Re: ports/52016: New port: lang/harbour -
stefan at fafoe.narf.at
Fri Jan 9 08:42:52 PST 2004
On Sat, Jan 10, 2004 at 02:03:57AM +1100, Bruce Evans wrote:
> - at least old standards seem to permit feature test macros to have no
> value (they may be empty, or perhaps more bizarre). The "+ 0" in the
> above is to handle this case, so that feature test with an empty value
> work the same as ones with value 0.
> #if _POSIX_SYNCHRONIZED_IO + 0 > 0
Undefined identifiers are replaced with 0 in a #if directive. Maybe
some ancient pre-C90 compilers didn't do that, but I think they can be
ignored these days.
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