Item12.cpp

// Item 12: Make sure that you copy all parts of an object
#include <iostream>
#include <string>

using namespace::std;

class Animal
{
 public:
 	Animal ( int aAge = 0 );
	Animal ( const Animal& rhs );
	Animal& operator = ( const Animal& rhs );
	
	int getAge ( ) {return age;}
	
 private:
 	int age;
};

Animal::Animal ( int aAge ): age ( aAge ) {}

Animal::Animal ( const Animal& rhs ):
 age ( rhs.age )
{}

Animal& Animal::operator = ( const Animal& rhs )
{
 age = rhs.age;
 return *this;
}

class Dog : public Animal
{
 public:
 	Dog ( int aAge=0, string aBreed='\0' );
	Dog ( const Dog& rhs );
	Dog& operator= ( const Dog& rhs );
	
	void ToString ( );
 private:
 	string breed;	 
};

Dog::Dog ( int aAge, string aBreed ): Animal(aAge),breed(aBreed) {}

// Call to base class copy constructor intentionally commented to demonstrate the error
Dog::Dog ( const Dog& rhs ):
//	  Animal ( rhs ),
	breed(rhs.breed)
{
 
}

void Dog::ToString ( )
{
 cout << "Age: " << getAge() << "; Breed: " << breed << endl; 
}

// Call to base class operator= intentionally commented to demonstrate the error
Dog& Dog::operator= ( const Dog& rhs )
{
// Animal::operator=(rhs);
 breed = rhs.breed;
 return *this;
}

int main()
{
 Dog d1(10,"Bull Dog");
 cout << "Dog d: " << endl;
 d1.ToString();
 
 // Age should be 10 but remains zero
 Dog d2(d1);
 cout << endl << "Dog d2: " << endl;
 d2.ToString();
 
 Dog d ( 13, "Alsasian");

 Dog d3 ( 10, "Labrador" );
 
 // Age should become 13 but remains 10
 d3 = d;
 cout << endl << "Dog d3: " << endl;
 d3.ToString();
}