[Bug libstdc++/51365] cannot use final empty class in std::tuple

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51365

--- Comment #8 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-12-03 
12:06:08 UTC ---
patch implementing __is_final submitted for approval:
http://gcc.gnu.org/ml/gcc-patches/2011-12/msg00231.html