// Created by Igor Markov, Feb 17, 2001

// This program demonstrates the difference between a stack and a queue
// and also how to use them interchangeably
// (this is one of half a dozen possible approaches to Project 1)

#include <queue>
#include <stack>
#include <iostream>

typedef int MyWeirdClass; // can be something else in your application

class STLContainerWrapper
{
   stack<MyWeirdClass> _st;
   queue<MyWeirdClass> _qu;

   public:
     enum Mode { BehaveLikeAStack, BehaveLikeAQueue };

   private:

     Mode  _mode;
 
   public:

   STLContainerWrapper(Mode mode) :_mode(mode) {}
   bool isEmpty() 
        { return ( _mode== BehaveLikeAStack ? _st.empty() : _qu.empty()) ; }
   MyWeirdClass removeElement() 
        {  
           MyWeirdClass tmp;
           if (_mode== BehaveLikeAStack){ tmp=_st.top();   _st.pop(); }
           else                         { tmp=_qu.front(); _qu.pop(); }
           return tmp;
        } 
   void addElement(MyWeirdClass elt)
        {  
           if (_mode== BehaveLikeAStack)  _st.push(elt);
           else                           _qu.push(elt);
        } 
};

int main()
{

   STLContainerWrapper w1(STLContainerWrapper::BehaveLikeAStack);
   cout << " Let's run in the stack mode first :  adding 5, 6, 7 ..." << endl;
   w1.addElement(5);
   w1.addElement(6);
   w1.addElement(7);
   cout << " Remove those elements and see what the order is :" << endl;
   cout << w1.removeElement() << ", ";
   cout << w1.removeElement() << ", ";
   cout << w1.removeElement() << endl;
   
   STLContainerWrapper w2(STLContainerWrapper::BehaveLikeAQueue);
   cout << " Now run in the queue mode :  adding 5, 6, 7 ..." << endl;
   w2.addElement(5);
   w2.addElement(6);
   w2.addElement(7);
   cout << " Remove those elements and see what the order is :" << endl;
   cout << w2.removeElement() << ", ";
   cout << w2.removeElement() << ", ";
   cout << w2.removeElement() << endl;
}