On Thu, Dec 12, 2013 at 6:38 PM, Florian Weimer <fweimer@xxxxxxxxxx> wrote: > Is there a way to count the number of variadic macro arguments in C? > > I found a way to check if the list is empty: examine > sizeof(STR((__VA_ARGS__))) where STR is a macro that stringifies its > argument. If it is 3, __VA_ARGS__ is empty. I wonder if there is a less > hackish approach. > > The macro arguments are expressions, but not of a uniform type, so an > array-based approach does not work. > > -- > Florian Weimer / Red Hat Product Security Team #define PP_NARG( ...) PP_NARG_(__VA_ARGS__,PP_RSEQ_N()) #define PP_NARG_(...) PP_ARG_N(__VA_ARGS__) #define PP_ARG_N(_1,_2,_3,_4,_5,_6,_7,_8,_9,[..],_61,_62,_63,N,...) N #define PP_RSEQ_N() 63,62,61,60,[..],9,8,7,6,5,4,3,2,1,0 PP_NARG(A) 1 PP_NARG(A, B) 2 ........
