Sams Teach Yourself C++ in 21 Days

void append( int value );

int is_present( int value ) const;

int is_empty() const { return head == 0; }

int count() const { return theCount; }

private:

class ListCell

{

public:

ListCell( int value, ListCell *cell = 0):val(value),

next(cell){}

int val;

ListCell *next;

};

ListCell *head;

ListCell *tail;

int theCount;

};

2. Write the implementation for the Listclass (nontemplate) version.


3. Write the template version of the implementations.


4. Declare three list objects: a list of Strings, a list of Cats, and a list of ints.
   5.BUG BUSTERS:What is wrong with the following code? (Assume the Listtem-
   plate is defined and Catis the class defined earlier in the book.)
   List Cat_List;
   Cat Felix;
   CatList.append( Felix );
   cout << “Felix is “
   << ( Cat_List.is_present( Felix ) )? “” : “not “
   << “present” << endl;
   Hint(this is tough): What makes Catdifferent from int?


5. Declare friend operator==for List.


6. Implement friend operator==for List.


7. Does operator==have the same problem as in Exercise 5?


8. Implement a template function for swapthat exchanges two variables.

714 Day 19