// Temp2.cpp

#include <iostream>
#include <string>

class Y
{
public:
  Y() { std::cout << "\n  Y()"; }
};

class X : public Y
{
public:
  X() { std::cout << "\n  X()"; }
  int operator[](const std::string& str) 
  {  
    return str.size();
  }
};

int main()
{
  int i = X()["a string"];
  std::cout << "\n  length of \"a string\" = " << i << "\n\n";

  return 0;
}