#include <iostream.h>

//
// Class Definition
//

class Glass{
  private:
    int volume;
    int filled;
  public:
    int fill(int);
    int drink(int);
    int empty();
    int content();
    Glass(int);
    ~Glass();
};

//
// Implementation of Member Functions
//

Glass::Glass(int the_volume)
{
  volume = the_volume;
  filled = 0;
}

Glass::~Glass()
{}

int Glass::fill(int quantity)
{
  int free = volume - filled;
  if (quantity > free) 
  {
    filled = volume;
    return free;
  }else{
    filled += quantity;
    return quantity;
  }
}

int Glass::drink(int quantity)
{
  int to_drink;
  if (quantity > filled)
  {
    filled = 0;
    return to_drink;
  }else{
    filled -= quantity;
    return quantity;
  }
}

int Glass::empty()
{
  int to_spill;
  filled = 0;
  return to_spill;
}

int Glass::content()
{
  return filled;
}

//
// Main
//

void main()
{
  int e;
  Glass aGlass(1000);

  e=aGlass.fill(500);
  cout << "Filling glass with: " << e << endl;
  
  e=aGlass.drink(250);
  cout << "Drinking: " << e << endl;
  cout << "The glass contains: " 
    << aGlass.content() << endl;
  aGlass.empty();
}