[Bug libstdc++/50529] New: std::vector::erase invokes undefined behavior with empty range

[delong.j at fb dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50529

             Bug #: 50529
           Summary: std::vector::erase invokes undefined behavior with
                    empty range
    Classification: Unclassified
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: libstdc++
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: delon...@fb.com


If you call vector erase() with an empty range, it invokes std::move() with an
output iterator inside of the source range.  (I.e. it tries to move all the
elements onto themselves.)  This causes problems if some of the elements don't
support self move-assignment (e.g. if they are other std::vectors).