Overriding virtual member function containing constant

Question

How can I override a virtual member function of the following type:

virtual AnimalId func(int index) const

where AnimalId is a typedef unsigned int

I tried several ways but either ending up by an error that I don't give output or that I don't have an overrider at all. I saw on some website that maybe I need to use static const in order to do this, but I don't know how.

Answer 1

Did you mean something like: (Note, you have to remove override if you compile for C++03)

typedef unsigned int AnimalId;

class Base
{
public:
    virtual ~Base() {}
    virtual AnimalId func(int index) const { return 0; }
};

class Derived : public Base
{
public:
    AnimalId func(int index) const override { return 42; }
};

Answer 2

In order to override method of signature

virtual AnimalId func(int index) const

declared in base class Base, you have to define function with same signature in derived class:

class Derived : public Base {
public:
   virtual AnimalId func(int index) const
     {
         return 43;  // I am using 43 because I think this is
                     // so much underestimated in favor of 42
     }
    //...
};

Or you can type override kryword to be more explicit:

class Derived : public Base {
public:
   virtual AnimalId func(int index) const override
     {
         return 43 & 45;
     }
    //...
};