operator==, operator!= in the class synopsis

I think the new preferred style is to put these as hidden friends
inside the class. This presumably helps overload resolution
performance.  Also, operator!= can go, because the new operator
rewrite rules will automatically obtain != from operator==.

I think it should be "If the container is empty" (add definite article, for
improved English happiness).
Also, we can't have compile-time constraints ("MoveInsertable") apply depending
on run-time conditions ("empty").

The "iterators have relational operators" specification needs to
materialize in normative wording.  Just saying that they "have" those
operators is not enough; you also need to say what the semantics are.


Jens