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

Solution 1: add one more virtual function:

enum DerivedType
{
    One,
    Two,
    ...
};

class base 
{ 
public: 
   ~base(){} 
   virtual void foo() {}
   virtual DerivedType GetType() = 0;
}; 

template  
class derived1 : public base 
{ 
   virtual void foo() {};
   virtual DerivedType GetType() { return One; }
}; 

template  
class derived2 : public base 
{ 
   virtual void foo() {};
    virtual DerivedType GetType() { return Two; }
}; 

Solution 2: using tag classes:

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

class Derived1Tag
{ };

class Derived2Tag
{ };

template 
class Derived1 : public Base, public Derived1Tag
{ };

template 
class Derived2 : public Base, public Derived2Tag
{ };


int main(int argc, char** argv)
{
    Derived1 d1;
    Derived2 d2;

    cout << dynamic_cast((Base*)&d1) << endl;
    cout << dynamic_cast((Base*)&d2) << endl;

    return 0;
}