If the Hidden virtual functions option is on, the compiler generates a warning if you declare a non-virtual member function in a subclass that hides an inherited virtual function in a superclass. One function hides another if it has the same name but a different argument types. For example:

class A {
    public:
        virtual void f(int);
        virtual void g(int);
};

class B: public A {
    public:
        void f(char);               // WARNING:  Hides A::f(int)
        virtual void g(int);  // OK: Overrides A::g(int)
};    

The Hidden virtual functions option corresponds to the pragma warn_hidevirtual, described at "warn_hidevirtual." To check whether this option is on, use __option (warn_hidevirtual). See "Checking Options" for information on how to use this directive.