c++ using declaration, scope and access control

Question

Typically the \'using\' declaration is used to bring into scope some member functions of base classes that would otherwise be hidden. From that point of view it is only a me

Answer 1

The declaration

using C::a

brings "a" to the local naming scope so that you can later use "a" to refere to "C::a"; since that, "C::a" and "a" are interchangeable as long as you don't declare a local variable with name "a".

The declaration does not change access rights; you can access "a" in the subclass only because "a" is not private.