オブジェクトtemplateじゃんけん [C++]

#include <iostream>
#include <string>

class Hand
{
  public:
    virtual ~Hand() {}
    std::string
      to_string() const
      { return _to_string(); }
  private:
    virtual std::string
      _to_string() const = 0;
};
std::ostream&
operator<<(
    std::ostream& os,
    const Hand& h
    )
{ return os << h.to_string(); }

class Scissors 
: public Hand
{
  std::string
    _to_string() const
    { return "ちょき"; }
};

class Stone
: public Hand
{
  std::string
    _to_string() const
    { return "ぐぅ"; }
};

class Paper
: public Hand
{
  std::string
    _to_string() const
    { return "くぱぁ"; }
};

class Result
{
  public:
    virtual ~Result() {}
    std::string
      to_string() const
      { return _to_string(); }
  private:
    virtual std::string
      _to_string() const = 0;
};
std::ostream&
operator<<(
    std::ostream& os,
    const Result& r
    )
{ return os << r.to_string(); }

template<class WINNER>
class Win
: public Result
{
  std::string
    _to_string() const
    { return WINNER().to_string() + "の勝ち"; }
};

class Even
: public Result
{
  std::string
    _to_string() const
    { return "あいこ"; }
};

template<class L, class R>
struct Judge
{ typedef Even  Message; };

template<>
struct Judge<Scissors, Stone>
{ typedef Win<Stone>  Message; };
template<>
struct Judge<Scissors, Paper>
{ typedef Win<Scissors>  Message; };
template<>
struct Judge<Stone, Scissors>
{ typedef Win<Stone>  Message; };
template<>
struct Judge<Stone, Paper>
{ typedef Win<Paper>  Message; };
template<>
struct Judge<Paper, Stone>
{ typedef Win<Paper>  Message; };
template<>
struct Judge<Paper, Scissors>
{ typedef Win<Scissors>  Message; };
  

template<class L, class R>
class Match
{ };

template<class L, class R>
std::ostream&
operator<<(
    std::ostream& os,
    Match<L, R> m
    )
{
  return os <<
    L().to_string() <<
    " 対 " <<
    R().to_string() <<
    " = " <<
    typename Judge<L,R>::Message();
}

int main()
{
  std::cout << Match<Stone,     Stone>()    << "\n"
            << Match<Stone,     Scissors>() << "\n"
            << Match<Stone,     Paper>()    << "\n"
            << Match<Scissors,  Stone>()    << "\n"
            << Match<Scissors,  Scissors>() << "\n"
            << Match<Scissors,  Paper>()    << "\n"
            << Match<Paper,     Stone>()    << "\n"
            << Match<Paper,     Scissors>() << "\n"
            << Match<Paper,     Paper>()    << "\n";
  return 0;
}

え？ランダム？思考ルーチン？？ ナニソレオイシイノ? (´ー｀y-~

16:25追記 Stone vs Paper で Stoneが勝っちゃってたので修正。 orz