// abstract class linearList
// abstract data type specification for linear list data structure
// all methods are pure virtual functions

#ifndef linearList_
#define linearList_
#include <iostream>

using namespace std;

template<class T>
class linearList 
{
   public:
      virtual ~linearList() {};
      virtual bool empty() const = 0;
                  // return true iff list is empty
      virtual int size() const = 0;
                  // return number of elements in list
      virtual T& get(int theIndex) const = 0;
                  // return element whose index is theIndex
      virtual int indexOf(const T& theElement) const = 0;
                  // return index of first occurence of theElement
      virtual void erase(int theIndex) = 0;
                  // remove the element whose index is theIndex
      virtual void insert(int theIndex, const T& theElement) = 0;
                  // insert theElement so that its index is theIndex
      virtual void output(ostream& out) const = 0;
                  // insert list into stream out
};
#endif