//Listing 12.3

 // Passing references to objects

 #include <iostream>

 

 class SimpleCat

 {

 public:

     SimpleCat();

     SimpleCat(SimpleCat&);

     ~SimpleCat();

 

     int GetAge() const { return itsAge; }

     void SetAge(int age) { itsAge = age; }

 

 private:

     int itsAge;

 };

 

 SimpleCat::SimpleCat()

 {

     std::cout << "Simple Cat Constructor...\n";

     itsAge = 1;

 }

 

 SimpleCat::SimpleCat(SimpleCat&)

 {

     std::cout << "Simple Cat Copy Constructor...\n";

 }

 

 SimpleCat::~SimpleCat()

 {

     std::cout << "Simple Cat Destructor...\n";

 }

 

 const SimpleCat & FunctionTwo (const SimpleCat & theCat);

 

 int main()

 {

     std::cout << "Making a cat...\n";

     SimpleCat Frisky;

     std::cout << "Frisky is " << Frisky.GetAge() 

               << " years old\n";

 

     int age = 5;

     Frisky.SetAge(age);

     std::cout << "Frisky is " << Frisky.GetAge() 

               << " years old\n";

 

     std::cout << "Calling FunctionTwo...\n";

     FunctionTwo(Frisky);

     std::cout << "Frisky is " << Frisky.GetAge() 

               << " years old\n";

     return 0;

 }

 

 // functionTwo passes a ref to a const object

 const SimpleCat & FunctionTwo (const SimpleCat & theCat)

 {

     std::cout << "Function Two. Returning...\n";

     std::cout << "Frisky is now " << theCat.GetAge()

               << " years old \n";

     // theCat.SetAge(8);   const!

     return theCat;

 }