// File: C++Examples/Stacks/main.cpp 
//
// This is the C++ version of the C example
//
//    ../CExamples/OO_pgm_in_C/
//
// One would not normally write a stack in C++
// this way, but use the STL stack adaptor.
//
// The C++ version is distinguished from
// the C version in that the main program is
// not generic.  For that purpose, one could have a
// function
//
//    stack* make_stack();
//
// in array_stack.cpp that is loaded at link time.
// Vice-versa, the C version could store a pointer
// to the new_stack() in struct stack, so that
// both list_stacks and array_stacks can be used
// in main.
//
// Reference:
// http://users.cs.duke.edu/~elk27/bibliography/96/EKM96.pdf

#include <iostream>
#include "array_stack.h"

// for STL stack adaptor below
#include <stack>
#include <vector>
#include <iterator>

 // Using the STL stack adaptor
 typedef std::stack< int, std::vector<int> > stl_stack;

 std::ostream& operator<<(std::ostream& os, const stl_stack& S)
 // print stack contents by popping a copy of the stack
 {stl_stack& S2 = *(new stl_stack(S));
  os << "STL stack contents: ";
  while(!S2.empty())
    {os << S2.top() << " "; S2.pop();}
  os << " bottom";
  delete &S2;
  return os;
 }//operator<<

 // second solution: make a subclass to access
 // protected member "Container c" in stl_stack (C++ standard, Section 23.2.3.3)
 class sub_stack : public stl_stack
 {
  friend std::ostream& operator<<(std::ostream& os, const sub_stack& Sub);
 };//class substack

 std::ostream& operator<<(std::ostream& os, const sub_stack& Sub)
 // print stack contents by traversing container
 {std::ostream_iterator<int> out(os, " ");
  os << "Sub stack contents: ";
  std::copy( Sub.stl_stack::c.begin() // resolve scope of member c to base class
           , Sub.c.end() // use inheritance of member c of base claaaaaaaaass
           , out);
  os << "bottom";
  return os;
 }//operator<<

// can't use namespace std because conflict with "stack" name

int main(void)
// Test the stack 
{int i;
 stack& st = *(new array_stack());

 std::cout << st << std::endl;
 for (i=1; i < 6; i++)
     { std::cout <<  "Pushing " << i << std::endl;
       st.push(i);
       std::cout << st << std::endl;
     }
 
 for (i=0; i < 3; i++)
     { std::cout << "Popping " << st.pop() << std::endl;
       std::cout << st << std::endl;
     }

// use of STL stack container adapter
 stl_stack& stl_st = *(new stl_stack());
 std::cout << std::endl  << stl_st << std::endl;
 for (i=1; i < 6; i++)
     { std::cout <<  "Pushing " << i << std::endl;
       stl_st.push(i);
       std::cout << stl_st << std::endl;
     }

 for (i=0; i < 3; i++)
     { std::cout << "Popping " << stl_st.top() << std::endl;
       stl_st.pop();
       std::cout << stl_st << std::endl;
     }

// use subclass of STL stack container adapter
 sub_stack& sub_st = *(new sub_stack());
 std::cout << std::endl  << sub_st << std::endl;
 for (i=1; i < 6; i++)
     { std::cout <<  "Pushing " << i << std::endl;
       sub_st.push(i);
       std::cout << sub_st << std::endl;
     }

 for (i=0; i < 3; i++)
     { std::cout << "Popping " << sub_st.top() << std::endl;
       sub_st.pop();
       std::cout << sub_st << std::endl;
     }

 delete &st;
 delete &stl_st; delete &sub_st;
 return 0;
}