290                                                     10. 

  .         
 ,     .  - 
   ,    (  ) -
 ,     .      -
    .    
        -
 -.  -    -
   ;      -
 .        
 ,      - this. 
,     ,    -
      .    
   virtual.
  .

  virt_sel.cpp

//  

class  {
public:

int i ;

virtual void print_i() const

{ cout  i  "  "  endl; }
};

class D : public  {
public:

// 
void print__i() const

{ cout  i  "  D"  endl; .}

int mainf)

{

 b;

B* pb = &b;         //   
Dd;

d.i = 1 + (b.i = 1);

pb -> print_i();    // B::print_i()
pb = &d;            //   D
pb -> print_i();    // D::print_i()

}

    :

1  

2  D