[Bug libstdc++/53339] unordered_map::iterator requires Value to be complete type

[eltoder at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53339

--- Comment #1 from Eugene Toder <eltoder at gmail dot com> 2012-05-13 22:22:54 UTC ---
Created attachment 27394
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27394
Quick and dirty proof-of-concept patch