c++ - How do you implement the destructor in CRTP? -


are destructors required virtual when implementing curiously recurring template pattern (crtp)? , if not, proper non-virtual implementation?

i'll provide example make things easier:

template<typename t> class base { public:     virtual ~base()     {         // should virtual? non-virtual?         std::cout << "base::~base()\n";     } };  class derived : public base<derived> { public:     ~derived() override     {         std::cout << "derived::~derived()\n";     } };  int main() {     base<derived>* b = new derived;     delete b; }

result:

derived::~derived() base::~base()

(live sample here)

edit: updated example use runtime polymorphism virtual destructor required proper cleanup.

a crtp base class no different other base class in sense. need virtual destructor if going delete object of type derived via pointer base<derived>. otherwise, virtual destructor not required.

base<derived>* b = new derived; delete b; // base<derived>::~base<derived> must virtual

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