public class Battle<T1,T2> where T1:Character where T2 : Character {
  T1 _c1;
  T2 _c2;
  
  public Battle(T1 c1, T2 c2){
    _c1 = c1;
    _c2 = c2;
  }
  
  public void Do() {
    _c1.Attack(_c2);  //템플릿 함수지만 Character를 상속한 애들만 받을 수 있기 때문에 호출가능.
    _c2.Attack(_c1);
  }
}

public class Character{
     public virtual void Attack(Character target){}
}

public class Hero: Character {

}

public class Enemy : Character {
}


public static class Program{

  static void Main(){
      var h= new Hero();
      var e = new Enemy();
      
      var b = new Battle<Hero,Enemy>(h,e);
      b.Do();
  }
}