https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107022
--- Comment #8 from Jens Maurer <jens.maurer at gmx dot net> --- I understand we're in a tangled web of partially-complete class rules here, but the standard does give you the expectation that the inner class is complete at its closing brace: [class.pre] p2 says: "A class is considered defined after the closing brace of its class-specifier has been seen even though its member functions are in general not yet defined."
