Original Post
What are the rules for copy/conversion (not sure of the right term in this case) a base object from a derived one? Does the compiler automatically generate a copy constructor and cast, or generate a conversion one? For example: The output is 5. If I make the copy constructor of Bar private, the code doesn't compile, so it seems the compiler is using it to do the construction. However, why is it then that if I make it explicit, it's still doing it? I thought that explicit disallows conversions of constructor arguments! Is this a compiler issue, or is there a language rule excepting inheritance-related classes from explicit?
class Bar
{
public:
Bar(Bar const &o) : _m(o._m) {}
void Print(void) : { cout << _m << endl; }
protected:
Bar(int const i) : _m(i) {}
int _m;
};
class Foo : public Bar
{
public:
Foo(void) : Bar(5) {}
};
Foo one;
Bar two(one);
two.Print();
