http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49974
--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-04-08 18:15:04 UTC --- As pointed out in PR 52901 comment 3, this missing warning is likely to bite people misusing std::move like so: X&& f() { X x; return std::move(x); }