nA using declaration can bring any hidden public or protected base class member into the scope of the derived class.
nThese members act as
overloaded members of the derived
class.
nHowever, such members remain hidden in situations where the argument list is the same as the same named member in the derived class.
nIn the following example, the using declaration makes the function taking the double accessible to clients of the derived class. But, the function taking the int is
still hidden in the derived
class by declaring a derived class member
function that has the same signature.