Downcasting from base pointer to templated derived types

Question

I have the following hierarchy:

class base
{
public:
   virtual ~base(){}
   virtual void foo() {}
};

template 
class derived1 : public base
{         


        

Answer 1

Move the logic which depends on the type into the type.

Instead of:

if (dynamic_cast*>(b) ||
    dynamic_cast*>(b) ||
    dynamic_cast*>(b))
  std::cout << "is derived1";
else if (dynamic_cast*>(b) ||
    dynamic_cast*>(b) ||
    dynamic_cast*>(b))
  std::cout << "is derived2";

add a virtual print_name() const function to base, and then do:

void example() {
    std::unique_ptr b(new derived1());
    b->print_name();
}
class base
{
public:
   ~base(){}
   virtual void foo() {}
   virtual void print_name() const = 0;
};

template 
class derived1 : public base
{
   virtual void foo() {}
   virtual void print_name() const {
       std::cout << "is derived1";
   }
};

template 
class derived2 : public base
{
   virtual void foo() {}
   virtual void print_name() const {
       std::cout << "is derived2";
   }
};