Dynamic Casts

Dynamic casts allow us to transform from a base class to a derived class and perform non-polymorphic actions on it.

Considering the following code:

class Animal {
    void breathe();
};

class Feline : public Animal {
    void run();
};

int main() {
    Animal *p_animal = new Feline;
    Feline *p_feline = dynamic_cast<Feline*>(p_animal);
    if (p_feline) {
        p_feline->run();
    }
}

We can cast the animal pointer to a feline pointer using dynamic_cast and call feline specific methods using the resulting pointer. The code to do the casting with smart pointer is just as simple:

std::shared_ptr<Animal> p_animal = std::make_shared<Feline>(Feline();
std::shared_ptr<Feline> p_feline = std::dynamic_pointer_cast<Feline>(p_animal);
p_feline->run();

Feline *p_feline = dynamic_cast<Feline*>(&animal_ref);