Question

Let us assume I have two classes:

class Base{};

class Derived: public Base{};

none has d’tor, in this case if I declare about variables:

Base b;
Derived d;

my compiler will produce for me d’tors, my question is, the default d’tors of the b and d will be virtual or not?

Answer 1

my question is, the d’tors of the b and d will be virtual or not

No, they won’t. If you want a virtual destructor, you will have to define your own, even if its implementation is exactly the same as that which would be supplied by the compiler:

class Base {
  public:
    virtual ~Base() {}
};