[ 2010-02-25 Alisdair adds: ]

vector<bool>::reference is a nested class, and not a typedef. It should be removed from the list of containers when this change is made.

In general, I am uncomfortable placing this reference requirement on each container, as I would prefer to require:

is_same<Container::reference, Container::iterator::reference>

This distinction is important, if we intend to support proxy iterators. The iterator paper in the pre-Pittsburgh mailing (N3046) does not make this proposal, but organises clause 24 in such a way this will be much easier to specify.

The changes to clause 20 remain important for all the reasons Pete highlights.