C++ Programming :: Namespaces - Discussion

#include <iostream>
        using namespace std;
        namespace extra
        {
            int i;
        }
        void i()
        {
            using namespace extra;
            int i;
            i = 9;
            cout << i;
        }
        int main()
        {
            enum  letter { i, j};
            class i { letter j; };
            ::i();
            return 0;
        }