It's an easy thing to do, but the for-loop ends up being pretty ugly, so
hide it behind the macro.
It would be even prettier with one of the (few) useful C99 features:
local for-loop variables. However, gcc needs special command line
options, and other compilers may not do it at all. So instead of doing
#define for_each_dive(_x) \
for (int _i = 0; ((_x) = get_dive(_i)) != NULL; _i++)
we require that the user declare the index iterator too, and the use
syntax becomes
for_each_dive(idx, dive) {
... use idx/dive here ...
}
And hey, maybe somebody actually will want to use the index, so maybe
that's not all bad.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>