///////////////////////////////////////////////////////////////////
// operations.cpp - Solution of MT#2-Q5, MT#3-Q6, and MT#4-Q8    //
//                                                               //
// This is a demo showing how what happens when some polymorphic //
// code executes.                                                //
///////////////////////////////////////////////////////////////////

#include <iostream>
#include <string>
typedef std::string str;

class B
{
public:
  virtual ~B() {};
  str say() { return typeid(*this).name(); }
  virtual B* make() { return new B(*this); }
};

class D : public B
{
public:
  D* make() { return new D(*this); }
};

class A { str say() { return "class A"; } };

class B2
{
public:
  virtual ~B2() {};
  str say() { return typeid(*this).name(); }
};

class D2 : public B2
{
public:
  A a;
};


void fun1(B2 b[], int size)
{
  for(int i=0; i<size; ++i)
    std::cout << "\n  " << b[i].say();
}

void fun2(D2 d[], int size)
{
  for(int i=0; i<size; ++i)
    std::cout << "\n  " << d[i].say();
}

class D3
{
public:
  D3() {}
  D3& Do(int i)
  {
    std::cout << "\n  doing " << i;
    return *this;
  }
};

int main()
{
  std::cout << "\n  " << B().say();
  std::cout << "\n  " << D().say();
  std::cout << "\n\n";

  B& obj1 = *B().make();
  B& obj2 = *D().make();
  B& obj3 = *obj2.make();
  B  obj4 = *D().make();
  D  obj5 = *D().make();
  std::cout << "\n  " << obj1.say();
  std::cout << "\n  " << obj2.say();
  std::cout << "\n  " << obj3.say();
  std::cout << "\n  " << obj4.say();
  std::cout << "\n  " << obj5.say() << "\n\n";

  std::cout << "\n  " << B2().say();
  std::cout << "\n  " << D2().say() << "\n\n";

  D2 ds[3];
  fun2(ds,3);
//  fun1(ds,3);  // will crash
  std::cout << "\n\n";

  D3().Do(1).Do(2).Do(3);
  std::cout << "\n\n";

  return 0;
}