Sams Teach Yourself C++ in 21 Days

Templates 679

19

21:

22: private:

23: int itsWeight;

24: };

25:

26: // extraction operator for printing animals

27: ostream& operator<<

28: (ostream& theStream, const Animal& theAnimal)

29: {

30: theStream << theAnimal.GetWeight();

31: return theStream;

32: }

33:

34: Animal::Animal(int weight):

35: itsWeight(weight)

36: {

37: // cout << “Animal(int)” << endl;

38: }

39:

40: Animal::Animal():

41: itsWeight(0)

42: {

43: // cout << “Animal()” << endl;

44: }

45:

46: Animal::~Animal()

47: {

48: // cout << “Destroyed an animal...” << endl;

49: }

50:

51: template <class T> // declare the template and the parameter

52: class Array // the class being parameterized

53: {

54: public:

55: Array(int itsSize = DefaultSize);

56: Array(const Array &rhs);

57: ~Array() { delete [] pType; }

58:

59: Array& operator=(const Array&);

60: T& operator[](int offSet) { return pType[offSet]; }

61: const T& operator[](int offSet) const

62: { return pType[offSet]; }

63: int GetSize() const { return itsSize; }

64: // friend function:

65: // template <class T>

66: friend ostream& operator<< (ostream&, const Array<T>&);

67:

68: private:

69: T *pType;

LISTING19.5 continued