https://gcc.gnu.org/bugzilla/show_bug.cgi?id=32039
--- Comment #8 from Harald van Dijk <harald at gigawatt dot nl> --- (In reply to Ville Voutilainen from comment #7) > This is invalid. [namespace.udecl]/3 says that if the declaration names > a constructor, the nested-name-specifier shall name a direct base, but if > the declaration names something else than a constructor, indirect bases are > fine. Yes, but you're ignoring p14 (now p17 in N4140) which was mentioned right in the initial report, which adds "The base class members mentioned by a using-declaration shall be visible in the scope of at least one of the direct base classes of the class where the using-declaration is specified." That is not limited to constructors, that is a separate requirement in the standard that GCC and clang both fail to implement.
