[Bug libstdc++/55043] 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 #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-10-23 22:28:52 UTC ---
This is due to the fact that _Hashtable::_Hashtable(_Hashtable&&) is not
declared noexcept.

I think we can just add 'noexcept' to the move ctor and move assignment op, at
least until I add proper C++11 allocator support to the unordered containers.