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#include <iostream>
using namespace std;
 
template < typename T >
class AA
{ private:
  protected :
 
  class BB 
  { public :
    T val ;
    BB() {}
    BB( const T& v ) : val(v) {}
  };
 
  BB * B ;
  public:
  AA()  { B= 0; }
  AA( const T& v ) 
  { B = new BB( v ) ; }
 
  virtual ~AA() { delete B ; }  
 
  void show()
  {  cout << B->val << endl ; }
 
  BB * getIn();
 
  void run() 
  { BB * b = getIn() ;
    cout << b->val << endl ;
  }  
};
 
template < typename T >
typename AA<T>::BB * AA<T>::getIn() 
{ return B ; }
 
 
template < typename T >
class CC : public AA<T> 
{ public :
  CC() : AA<T>(){};
  CC( const T& v ) : AA<T>(v) {}	  
  T doComplicated()
  { //typename AA<T>::BB * c = AA<T>::getIn() ;  //ok
    typename AA< T >::BB * c =  AA<T>::BB->B ;  // scratch 
    return c->val ;
  }    
};
 
void do1()
{ CC<int>  a(999) ; 
  a.show() ;
  a.run() ;
  cout << endl << "oops " << a.doComplicated() << endl ;
}
 
int main( int argc, char ** argv )
{ do1() ;
  return 0 ;
} |