Why does the following code produce this error even though c
is a struct and has public inheritance by default?
struct c
{
protected:
int i;
public:
c(int ii = 0) : i(ii) {}
virtual c* fun();
};
c* c::fun()
{
cout << "in c";
return &c();
}
class d : c
{
public:
d() {}
d* fun()
{
i = 9;
cout << "in d" << '\t' << i;
return &d();
}
};
int main()
{
c *cc;
d dd;
cc = ⅆ
cc->fun();
}
You need:
class d : public c
class
inheritance is private
by default.
When you privately inherit from a class
or a struct
, you explicitly say, among other things, that direct conversion from a derived type to a base type isn't possible.