Класс, который знает все свои экземпляры

class ClassWhoKnowsAllHisInstances
{
private:  
  static std::list<  ClassWhoKnowsAllHisInstances* > classList;

public:
  ClassWhoKnowsAllHisInstances()
  {  
    classList.push_back(this);
  }; 
  ~ClassWhoKnowsAllHisInstances()
  {  
    std::list< ClassWhoKnowsAllHisInstances* >::iterator it;
    it=(std::find(classList.begin(), classList.end(), 
        ( ClassWhoKnowsAllHisInstances* ) this));
    if(it!=classList.end())
      classList.erase(it);
  };
};