Accessing the Back of a Vector : vector back « vector « C++ Tutorial

1. C++ Tutorial
2. vector
3. vector back

#include <iostream>
#include <list>
#include <vector>

using namespace std;

template <class ForwIter>
void print(ForwIter first, ForwIter last, const char* title)
{
   cout << title << endl;
   while ( first != last)
      cout << *first++ << '\t';
   cout << endl;
}

class Card
{
   public:
   enum Suit { spades, clubs, hearts, diamonds };

   Card( int value = 1, Suit suit = spades );
   // value - 1 = Ace, 2-10, 11 = Jack, 12 = Queen, 13 = King

   int suit() const;
   int value() const;

   private:
   int value_;
   Suit suit_;
};

inline
Card::Card( int value, Suit suit )
   : value_( value ), suit_( suit )
{} // empty

inline
int Card::suit() const
{ return suit_; }

inline
int Card::value() const
{ return value_; }

// global function
ostream& operator<<( ostream& out, const Card& card )
{
   if( card.value() >= 2 && card.value() <= 10 )
      out << card.value();
   else
      switch( card.value() )
      {
         case  1: out << "Ace"; break;
         case 11: out << "Jack"; break;
         case 12: out << "Queen"; break;
         case 13: out << "King"; break;
         default: out << "Unknown value"; break;
      };

   out << " of ";
   switch( card.suit() )
   {
      case Card::spades:   out << "spades"; break;
      case Card::clubs:    out << "clubs"; break;
      case Card::diamonds: out << "diamonds"; break;
      case Card::hearts:   out << "hearts"; break;
      default:             out << "unknown suit"; break;
   }
   return out;
}

int main( )
{
   const int num_players = 2;
   vector< list<Card> > hands( num_players );

   // deal first player a hand
   hands[0].push_front( Card( 12, Card::hearts ) );
   hands[0].push_front( Card( 1,  Card::spades ) );
   hands[0].push_front( Card( 4,  Card::spades ) );

   // deal second player a hand
   hands[1].push_front( Card( 13, Card::diamonds ) );
   hands[1].push_front( Card( 12, Card::clubs ) );
   hands[1].push_front( Card( 2,  Card::hearts ) );
   const int num_plays = 3;
   bool discard[num_players][num_plays] = { { true, true, false },
                                            { true, false, false } };
   vector<Card> discard_pile;

   // simulate card play
   for( int i = 0; i < num_plays; ++i )
      for( int j = 0; j < num_players; ++j )

         // if discard and hand not empty...
         if( discard[j][i] && !hands[j].empty() )
         {
            discard_pile.push_back( hands[j].front() );
            hands[j].pop_front();
            cout << "Player " << (j+1) << " discarded a "
               << discard_pile.back() << endl;
         }// if pick up and discard pile not empty...
         else if( !discard[j][i] && !discard_pile.empty() )
         {
            hands[j].push_back( discard_pile.back() );
            cout << "Player " << (j+1) << " picked up a "
               << discard_pile.back() << endl;
            discard_pile.pop_back();
         }
}