https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81347
Jonathan Wakely <redi at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |rejects-valid Status|RESOLVED |NEW Last reconfirmed| |2017-07-17 Resolution|INVALID |--- Ever confirmed|0 |1 --- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> --- No, this is definitely a GCC bug: namespace A { template <class> class tree { template <class> friend class map; }; } A::tree<int> x; namespace A { template <class> class map { }; } using A::map;