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  1. #include <stdio.h>
  2.  
  3. #define __NARGS(_1, _2, _3, _4, _5, VAL, ...) VAL
  4. #define NARGS(...) (sizeof(#__VA_ARGS__) == sizeof("") ? 0 : __NARGS(__VA_ARGS__, 5,4,3,2,1))
  5.  
  6. #define FOO(...) NARGS(__VA_ARGS__)
  7.  
  8. int main()
  9. {
  10.   printf("%d\n", FOO());     // prints 0
  11.   printf("%d\n", FOO(/*comment*/));     // prints 0
  12.   printf("%d\n", FOO(1));    // prints 1
  13.   printf("%d\n", FOO(1, 2)); // prints 2
  14.  
  15.   return 0;
  16. }
  17.  
Success #stdin #stdout 0s 3340KB
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https://ideone.com/DV3p4W
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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