the problem about different treatment to __VA_ARGS__ when using VS 2008 and GCC

Question

I am trying to identify a problem because of an unusual usage of variadic macros. Here is the hypothetic macro:

#define va(c, d, ...) c(d, __VA_ARGS__)
#defi         


        

Answer 1

There is an easy way to deal with this problem:

#define exp(...) __VA_ARGS__
#define va(c, d, ...) c(d, __VA_ARGS__)
#define var(a, b, ...)  exp(va(__VA_ARGS__, a, b))

var(2, 3, printf, “%d %d %d\n”, 1);

This will do the trick on VS 2008 and it won't affect gcc