extern (C++, N) is it implemented?

[Alexandr Druzhinin via Digitalmars-d-learn]

This dlang.org/cpp_interface.html says I can do the following

// c++
namespace N {
        void someCppFunction();
}

// d
extern (C++, N) void someCppFunction();

but this http://dpaste.dzfl.pl/e2242263e1dc says I can't

Is this feature implemented?