[gtkmm] question about Gdk::Point::equal

[Silviu Minut <minutsil cse msu edu>]

In gtkmm-2.0/gdkmm/types.h, Gdk::Point has the following member function:

  bool equal(const Gdk::Point& rhs) const;

and it is called e.g. by the non-member 

inline bool operator==(const Point& lhs, const Point& rhs)
  { return lhs.equal(rhs); }


I couldn't find an implementation of Gdk::Point::equal() anywhere,
yet (naturally), operator==() works as expected:

int main()
{
    Gtk::Point A(1,1), B(2,2);
    cout << (A==B ? "equal" : "not equal") << endl;
    return 0;
} 

Can somebody explain what's the deal with the equal() function?