Why don't STL containers have virtual destructors?

Question

Does anyone know why the STL containers don\'t have virtual destructors?

As far as I can tell, the only benefits are:

• it reduces the size of an insta

Answer 1

Another solution to be able to subclass from STL containers is one given by Bo Qian using smart pointers.

Advanced C++: Virtual Destructor and Smart Destructor

class Dog {
public:
   ~Dog() {cout << "Dog is destroyed"; }
};

class Yellowdog : public Dog {
public:
   ~Yellowdog() {cout << "Yellow dog destroyed." << endl; }
};


class DogFactory {
public:
   static shared_ptr createYellowDog() { 
      return shared_ptr(new Yellowdog()); 
   }    
};

int main() {
    shared_ptr pd = DogFactory::createYellowDog();

    return 0;
}

This avoids the dillema with virtual destructors altogether.