[Bug libstdc++/55043] [4.7 Regression] issue with nesting unordered_map containing unique_ptr into vector

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55043

--- Comment #27 from Jonathan Wakely <redi at gcc dot gnu.org> 2013-01-16 10:52:57 UTC ---
Actually, now that the unordered containers do not inherit from Hashtable it
should be much easier to implement something like comment 17. When Daniel first
suggested it I thought it would be tricky given the current design of the
containers, but François changed them three days later.

I'll revert today's patch and fix it properly by making __is_copy_insertable
more accurate and removing the unordered container constructors when
appropriate.