http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59603
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> --- Even if swapping an object with itself is well-defined it's a waste of time, so we shouldn't do it. There's a discussion happening now with the C++ library working group to resolve whether self-move-assignment is user error or supposed to be allowed (i.e. whether the debug mode assertion is ok or not)
