Why is a member template from private base class introduced with a using declaration inaccessible?

Question

Consider the following (artificial) example:

class A {
 public:
  template <typename T>
  class C {};
};

class B : private A {
 public:
  using A::C;
};

int main() {
  B::C<int> c;
}

It compiles successfully with both GCC and Clang, but Visual C++ 2010 gives the following error:

test.cpp(13): error C2247: 'A::C' not accessible because 'B' uses 'private' to inherit from 'A'

Is this a bug in Visual C++ or this code is indeed invalid?

If C is not a template, the code compiles on all compilers.

Possibly related: http://stackoverflow.com/questions/12294422/template-private-inheritance-in-vc10-is-not-accessible — Jonathan Potter, Feb 16 '15 at 19:29
@JonathanPotter Thanks for the link. It looks somewhat related indeed. Too bad the answers there don't say which compiler is correct. — vitaut, Feb 16 '15 at 19:34
@T.C. I also think so although it might be as well a gap in the standard. — vitaut, Feb 16 '15 at 19:35

score 5 · Accepted Answer · answered Feb 16 '15 at 19:41

5

[namespace.udecl]/p18:

The alias created by the using-declaration has the usual accessibility for a member-declaration.

Not much to say here. The name B::C is publicly accessible, and the code is well-formed. Just another MSVC bug.

answered Feb 16 '15 at 19:41

T.C.

1 Answers1