A harder version of Programming Project 4 would be to write a class named List, similar to Project 4, but with all the following member functions:

■    Default constructor, List();

■    double List::front();_f which returns the first item in the list

■    double List::back();, which returns the last item in the list

■    double List::current();_t which returns the “current" item

■    void List::advance();_t which advances the item that current() returns

■    void List::reset(); to make current() return the first item in the list

■    void List::insert(double afterMe, double insertMe);, which inserts insertMe into the list after afterMe and increments the private: variable count.

■    int size();which returns the number of items in the list

■    friend istream& operator <<(istream& ins, double writeMe);

 The private data members should include the following:

  node* head;

  node* current;

  int count;

 and possibly one more pointer.

 You will need the following struct (outside the list class) for the linked list nodes:

  struct node

  {

  double item;

  node *next;

  };

 Incremental development is essential to all projects of any size, and this is no exception. Write the definition for the List class, but do not implement any members yet. Place this class definition in a file list.h. Then #include “list.h” in a file that contains int main(){}.Compile your file. This will find syntax errors and many typographical errors that would cause untold difficulty if you attempted to implement members without this check. Then you should implement and compile one member at a time, until you have enough to write test code in your main function.