[Bug libstdc++/60710] New: experimental::optional is using T::operator!=

[larsbj at gullik dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60710

            Bug ID: 60710
           Summary: experimental::optional<T> is using T::operator!=
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: larsbj at gullik dot net

When looking at n3793 it states that operator!= should be implemented
with !(t1 == t2), and not t1 != t2 as the implementation in gcc 4.9 is
doing. This is the case for both the operator!= implementations where
optional<T> is compared against T.

Also since optional should not put requirements on the contained type
other than operator== and operator>, operator!= are removed from the
tests in the suggested patch.