hashtable local iterator

[Paolo Carlini]

On 12/14/2011 01:49 AM, Paolo Carlini wrote:
>> - this new iterator type needs a pointer to its parent container to 
>> work which is quite unusual on normal iterators.
> On the spot, I cannot see anything wrong with this. Normally, when 
> such kinds of links are present one must be careful about what happens 
> when one of the two changes without telling the other. Are we risking, 
> I don't know, local iterators becoming invalid when they shouldn't?
In particular, I would double check swap, which is supposed to not 
invalidate any iterator.

Besides what the Standard literally says, constant complexity, I think 
it's very important from the QoI point of view that all the begin/end 
member functions are very simple, because user code normally ends up 
using those in loops, everywhere. If that means we have to use a little 
more memory, I think it's in general fine (previous double checking what 
the other implementations appear to be doing).

Please let us know asap how are we doing on this.

Paolo.