friend class declaration and using directive

Is the following example well-formed? ``` namespace N { class A; } using namespace N; class B { int i; friend class A; }; namespace N { class A { B m; int get() { return m.i; } }; } ``` This example compiled successfully with Clang 3.5, but failed with g++ 4.8.1 with the following: ``` main.cpp: In member function ‘int N::A::get()’: main.cpp:7:9: error: ‘int B::i’ is private int i; ^ main.cpp:14:30: error: within this context int get() { return m.i; } ^ ``` C++11 standard §7.3.1.2 p3 says, If the name in a `friend` declaration is neither qualified nor a template-id and the declaration is a function or an elaborated-type-specifier, the lookup to determine whether the entity has been previously declared shall not consider any scopes outside the innermost enclosing namespace. In example, `class A` is not member of innermost enclosing namespace (i.e. global namespace), but `class A` is introduced by using directive into global namespace.