Ordering of using namespace std; and includes?

Question

I recently saw this code being used in a source file in a C++ project:

using namespace std;
#include 

Ignoring all issues o

Answer 1

I don't think it's legal, but the standard isn't 100% clear about it. Basically, name lookup (as defined in §3.4) can't find a previous declaration of the namespace, because there isn't one. Everything hinges on whether:

using namespace std;

is a declaration of the namespace or not. And I don't see any text in §7.3.4 which says that a using-directive declares the nominated namespace. G++ allows your code, but IMHO, this is a bug.