[Bug libstdc++/49559] [C++0x] stable_sort calls self-move-assignment operator

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49559

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-06-28 10:45:11 UTC ---
(In reply to comment #3)
> note that the FDIS is *very* explicit about what move_backward does

Ah ok - but if move_backward has to do that then we should avoid calling it at
all when nothing needs to move, maybe in __move_merge_backward