language: C99 strict (gcc-4.7.2)
date: 320 days 4 hours ago
link:
visibility: public 
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#include <stdio.h>
 
#define PP_ARG_N( \
          _1,  _2,  _3,  _4,  _5,  _6,  _7,  _8,  _9, _10, \
         _11, _12, _13, _14, _15, _16, _17, _18, _19, _20, \
         _21, _22, _23, _24, _25, _26, _27, _28, _29, _30, \
         _31, _32, _33, _34, _35, _36, _37, _38, _39, _40, \
         _41, _42, _43, _44, _45, _46, _47, _48, _49, _50, \
         _51, _52, _53, _54, _55, _56, _57, _58, _59, _60, \
         _61, _62, _63, N, ...) N
 
#define PP_RSEQ_N()                                        \
         63, 62, 61, 60,                                   \
         59, 58, 57, 56, 55, 54, 53, 52, 51, 50,           \
         49, 48, 47, 46, 45, 44, 43, 42, 41, 40,           \
         39, 38, 37, 36, 35, 34, 33, 32, 31, 30,           \
         29, 28, 27, 26, 25, 24, 23, 22, 21, 20,           \
         19, 18, 17, 16, 15, 14, 13, 12, 11, 10,           \
          9,  8,  7,  6,  5,  4,  3,  2,  1,  0
 
#define PP_NARG_(...)    PP_ARG_N(__VA_ARGS__)    
 
#define PP_NARG(...)     (sizeof(#__VA_ARGS__) - 1 ? PP_NARG_(__VA_ARGS__, PP_RSEQ_N()) : 0)
 
int main()
{
    printf("PP_NARG(1, 2) =\t%d\n", PP_NARG(1, 2));
    printf("PP_NARG(1) =\t%d\n", PP_NARG(1));
    printf("PP_NARG() =\t%d\n", PP_NARG());
    return 0;
}