Re: why private virtual function?
Abhishek Padmanabh wrote:
On Mar 16, 1:46 am, "Alf P. Steinbach" <al...@start.no> wrote:
Example:
<code>
class Base
{
private:
void foo() {}
public:
void bar() {}
};
struct Mixin { void foo() {} };
class Derived: public Base, public Mixin
{
public:
void bar() { foo(); } // Uh oh.
};
int main()
{
Derived().bar();}
</code>
In each specific case there are simple workarounds, e.g. here a
'using'-declaration or qualification, but IMHO there's something not
quite right about the scheme.
using declaration does not work here and rightly so. Something that is
private as declared by the "owner"/the base class itself should not be
easy enough to break into to make it visible. If the derived class
Mixin::foo is public, there is no reason Derived can't call into it.
opts to take it (inherit) privately, using works and probably rightly
so as it is the decision of the derived class about what it wants.
Still, using declaration looks like a hack to circumvent the bad
decisions already taken or just a way to reuse code causing additional
coupling apart from what inheritance already causes.