list ADT (a general list) class list ublic t() List(const List& list) copy constructor LIston // destructor bool empty() consti double head( const // get the head element void add(double x)i // add to the head void delete(i // delete the head element void display() consti // output private: Or to define one function Double delete 0; Which deletes and returns the head element3 class List { public: List(); // constructor List(const List& list); // copy constructor ~List(); // destructor bool empty() const; // boolean function double head() const; // get the head element void add(double x); // add to the head void delete(); // delete the head element void display() const; // output private: … }; list ADT (a general list) Or to define one function: Double delete(); Which deletes and returns the head element