Fwd: Re: ports/52016: New port: lang/harbour - AClipper-compatible compiler

[Stefan Farfeleder]

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.

Regards,
Stefan Farfeleder