I have implemented the following interface:
template <typename T>
class Variable
{
public:
Variable (T v) : m_value (v) {}
virtual void Callback () = 0;
private:
T m_value;
};
A proper derived class would be defined like this:
class Derived : public Variable<int>
{
public:
Derived (int v) : Variable<int> (v) {}
void Callback () {}
};
However, I would like to derive classes where Callback
accepts different parameters (eg: void Callback (int a, int b))
.
Is there a way to do it?
This is a problem I ran in a number of times.
This is impossible, and for good reasons, but there are ways to achieve essentially the same thing. Personally, I now use:
struct Base
{
virtual void execute() = 0;
virtual ~Base {}
};
class Derived: public Base
{
public:
Derived(int a, int b): mA(a), mB(b), mR(0) {}
int getResult() const { return mR; }
virtual void execute() { mR = mA + mB; }
private:
int mA, mB, mR;
};
In action:
int main(int argc, char* argv[])
{
std::unique_ptr<Base> derived(new Derived(1,2));
derived->execute();
return 0;
} // main