https://gcc.gnu.org/bugzilla/show_bug.cgi?id=12944 Bug 12944 depends on bug 10437, which changed state.
Bug 10437 Summary: "using namespace" at global scope creates incorrect code https://gcc.gnu.org/bugzilla/show_bug.cgi?id=10437 What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |FIXED