c++ cannot convert derived class to base - c++

Question

I have a very simple base class/ derived class scenario:
#include <tchar.h>
#include <stdio.h>
#include <iostream.h>
#include <conio.h>
class BaseChannel{
private:
public:
virtual ~BaseChannel(){};
virtual void SayBoo( bool SelectAll)=0;
};
class gdbChannel: BaseChannel{
public:
void SayBoo(bool SelectAll) {if (SelectAll) cout<<"boo";}
};
class UsesChannel{
public:
BaseChannel * c;
};
int _tmain(int argc, _TCHAR* argv[])
{
gdbChannel gc;
UsesChannel uc;
// uc.c = &gc; //cannot convert gdbChannel* to BaseChannel*
uc.c = (BaseChannel*)&gc; // works
uc.c->SayBoo(true);
getch();
return 0;
}
My initial implementation, commented out above, will not compile. Can anyone explain why? I feel that since gdbChannel is explicitly an instance of BaseChannel the cast shouldn't be necessary.

Answer 1

That is because gdbChannel does not use public inheritance to derive from BaseChannel (the default for class types is private).
If public inheritance is what you wanted to express, just write:
class gdbChannel : public BaseChannel{
// ^^^^^^
public:
void SayBoo(bool SelectAll) {if (SelectAll) cout<<"boo";}
};