[Bug libstdc++/54314] [4.8 Regression] undefined references to 'construction vtable for std::ostream-in-std::basic_ostringstream<char, std::char_traits<char>, std::allocator<char> >'

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54314

--- Comment #25 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-01-28 11:27:51 UTC ---
I meant the ABI checkers only.  Anyway, on the other side given comments like:
   This mangling isn't part of the ABI specification; in the ABI
   specification, the vtable group is dumped in the same COMDAT as the
   main vtable, and is referenced only from that vtable, so it doesn't
   need an external name.  For binary formats without COMDAT sections,
   though, we need external names for the vtable groups.
and
Construction virtual tables are not exported because
they cannot be referred to from other object files;
their name is not standardized by the ABI.

perhaps making them hidden whenever possible is really desirable.