Hi,

the "Container requirements" section seems to say very little about
container iterators. IMO several important things are missing. In
particular, I suggest to add the following:

1) For a container type X, X::iterator is convertable to
X::const_iterator.
I couldn't find this guarantee even for the standard containers. Is this
an oversight? BTW, it would be nice if for reversible containers
X::reverse_iterator was convertable to X::const_reverse_iterator, too,
but this would require a change in the reverse_iterator spec, I think.

2) X::iterator and X::const_iterator must be of the same category.
This is IMO particularily important in the presence of algorithms
overloaded on iterator tags.

3) iterator_traits<X::iterator>::reference must be the same as
X::reference.
This is an issue only if reference classes are to be allowed ( which is
the case, I believe: see the vector<bool> thread ).

4) This one is actually a question: which functions short of swap and
assignment might invalidate iterators into the container? IMO the
standard should specify this. BTW, if begin and end are not allowed to
invalidate iterators I don't understand why X::iterator isn't required
to be at least of the forward iterator category.


Bye

Roman
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