// MT3Q2.cpp - what happens when?

#include <string>
#include <iostream>

class X
{
public:
  X() { 
    pStr = new std::string("default x"); 
    std::cout << "\n  X constructed";
  }
  X(const X& x) { 
    pStr = new std::string(*(x.pStr));
    std::cout << "\n  X copied";
  }
  ~X() { 
    delete pStr; 
    std::cout << "\n  X destroyed";
  }
  void take(std::string str)
  {
    delete pStr;
    pStr = new std::string(str);
  }
  const std::string say() { return *pStr; }
  X& operator=(const X& x) { 
    if(&x == this) return *this;
    delete pStr;
    pStr = new std::string(*(x.pStr)); 
    std::cout << "\n  X assigned";
    return *this;
  }
private:
  std::string* pStr;
};

X SomeFunction1(void)
{
  // return value optimization will eliminate
  // the copy in call below

  return X();
}

X SomeFunction2(void)
{
  // no return value optimization here
  // so you see the copy operation

  X x;
  x.take("some string");
  return x;
}

int main()
{
  X x1 = SomeFunction1();
  std::cout << "\n  " << x1.say() << "\n";

  X x2 = SomeFunction2();
  std::cout << "\n  " << x2.say() << "\n";

  x2 = SomeFunction2();
  std::cout << "\n  " << x2.say() << "\n\n";
}