Sams Teach Yourself C++ in 21 Days

6. The class must define a default constructor, a copy constructor, and an overloaded
   assignment operator.


7. STL stands for the Standard Template Library. This library is important because it
   contains a number of template classes that have already been created and are ready
   for you to use. Because these are a part of the C++ standard, any compiler support-
   ing the standard will also support these classes. This means you don’t have to
   “reinvent the wheel!”

Exercises

1. One way to implement this template:
   0: //Exercise 19.1
   1: template
   2: class List
   3: {
   4:
   5: public:
   6: List():head(0),tail(0),theCount(0) { }
   7: virtual ~List();
   8:
   9: void insert( Type value );
   10: void append( Type value );
   11: int is_present( Type value ) const;
   12: int is_empty() const { return head == 0; }
   13: int count() const { return theCount; }
   14:
   15: private:
   16: class ListCell
   17: {
   18: public:
   19: ListCell(Type value, ListCell cell =
   ➥0):val(value),next(cell){}
   20: Type val;
   21: ListCell next;
   22: };
   23:
   24: ListCell head;
   25: ListCell tail;
   26: int theCount;
   27: };


2. The following is one possible answer:
   0: // Exercise 19.2
   1: void List::insert(int value)
   2: {
   3: ListCell *pt = new ListCell( value, head );
   4:

864 Appendix D

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