isascii (was: Another pitfall. Signed chars and ctype.h)

[Ray Butterworth]

In article <2448 at ditsyda.oz> evans at ditsyda.oz (Bruce Evans) writes:
>Why doesn't ANSI C guarantee isdigit() (etc.) on *all* characters?

Then the missing isascii() wouldn't even be needed.
This was proposed to the Committee and rejected on the (incorrect)
grounds that it couldn't be implemented without the macro's having
to evaluate its arguments more than once.