C++ Programming :: Namespaces - Discussion

#include <iostream>
        using namespace std;
        namespace first
        {
            int var = 5;
        }
        namespace second
        {
            double var = 3.1416;
        }
        int main ()
        {
            int a;
            a = first::var + second::var;
            cout << a;
            return 0;
       }