comma_operator.cc

#include <iostream>
#include <list>

template <typename T>
class _basic_tuple {
  public:
   _basic_tuple() : _list() {}
   virtual ~_basic_tuple() {}

   _basic_tuple &operator , (T other) {
     _list.push_back(other);
     return const_cast<_basic_tuple&>(*this);
   }

   operator int () {
     return _list.size();
   }

   void dump() {
     std::cout << "( ";
     for(auto it : _list) {
       std::cout << it << " ";
     }
     std::cout << ")" << std::endl;
   }

  private:
    std::list<T> _list;
};

class _tuple {
  public:
    template<typename T>
    _basic_tuple<T> operator , (T val) {
      return _basic_tuple<T>(), val;
    }
} Tuple;

int main(int argc, char * argv[]) {
  (Tuple, 1, 2).dump();
  (Tuple, "hello", "world").dump();
  int count = (Tuple, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
  std::cout << count << std::endl;
  return 0;
}

comma_output

( 1 2 )
( hello world )
10