2009/11/16 Surya Kiran Gullapalli <suryakiran.gullapalli@gmail.com>

Definition of PP_NARG is here: http://groups.google.com/group/comp.std.c/browse_thread/thread/77ee8c8f92e4a3fb/346fc464319b1ee5

This does not seems to be working, I keep getting the error C4003, not enough actual parameters for macro 'PP_ARG_N'

GCC says, PP_ARG_N expects 65 args, where as it is getting only 3. I'm kinda lost here .

Hm... that's because both branches of BOOST_PP_IF always get evaluated. We need to evaluate only one of them.

#define FOO_ARGS(...) \

BOOST_PP_IF( \

BOOST_PP_EQUAL(PP_NARG(__VA_ARGS__), 2), \

(__VA_ARGS__, 0), \

(__VA_ARGS__))

#define FOO(...) BOOST_PP_EXPAND(FOO_IMPL FOO_ARGS(__VA_ARGS__))

I'm attaching a complete solution.

Roman Perepelitsa.