So basically, in this code I create interface (abstract class) and then derived from it.
struct IPrintable
{
virtual void Print() = 0;
};
struct Base : public IPrintable
{
void Print()
{
std::cout << "Print from Base\n";
}
};
//And another class after that
struct A_Struct : public Base
{
};
After that in main function I create A_Struct and 3 pointer to it :
int main()
{
A_Struct myA;
IPrintable* Printp = &myA;
Base* Basep = &myA;
A_Struct* Ap = &myA;
//And of course we calling Print method
Printp->Print();
Basep->Print();
Ap->Print();
system("Pause");
return 0;
}
And everything is fine. BUT if we have need to add another case of Print just to A_Struct like so:
struct A_Struct : public Base
{
void Print(int myI)
{
std::cout << "Print num : " << myI << " from A_Struct\n";
}
};
The program will say "'A_Struct::Print': function does not take 0 arguments", which is mean that compiler can't find function Print().
We can fix this error by casting Ap pointer to IPrintable* like so:
((IPrintable*)Ap)->Print();
And everything will be fine again. But my question is: Why does this error even appear? Why it can't find overridden function by default?
