Override a member function with different return type

Question

Consider the example below:

#include 

using namespace std;

class base
{
   public:
      virtual int func()
      {
         cout <<          


        

Answer 1

If you want to override, you should try to use template.

See the following:

#include 

using namespace std;

class base
{
   public:
      template X func()
      {
         cout << "vfunc in base class\n";
         return static_cast(0);
      }  
};    

class derived: public base
{
   public:
      template X func()
      {
         cout << "vfunc in derived class\n";
         return static_cast(2);
      }  
};    

int main()
{
   derived *bptr = new derived;
   cout << bptr->func() << endl;
   cout << dynamic_cast(bptr)->func() << endl;

   derived *bptr2 = new derived;
   cout << bptr->func() << endl;
   cout << dynamic_cast(bptr)->func() << endl;


   return 0;
}

Of course, you dont need to declare it on two different class that way, you could do:

class base
{
   public:
      int func()
      {
         cout << "vfunc in base class\n";
         return 0;
      }  

      double func(){
        cout << "vfunc for double class\n";
        return 2.;

      }
};