#define SECOND(a, b, ...) b

#define IS_PROBE(...) SECOND(__VA_ARGS__, 0)
#define PROBE() ~, 1

#define NOT(x) IS_PROBE(_NOT_ ## x)
#define _NOT_0 PROBE()

Should be 1: NOT(0)
Should be 0: NOT(1)
Should be 0: NOT(not zero)
Should be 0: NOT()