Re: List container strawman 1.3

[Darren New <dnew@san.rr.com>]

Ted Dennison wrote:
> The list itself will have to
> keep a mini-list of iterators to support invalidating iterators whoose
> pointed-to item is removed. 

This could be done by checking at the time of access thru the invalid
iterator, rather than by checking during deletes.

For efficiency, keep track in each iterator and each list head the
number of deletes (or other operations that might invalidate an
iterator) that have occurred. If an iterator is accessed when that
counter in the iterator is smaller than the counter in the list it's
iterating, run through the list (O(N)) and check if the iterator is
pointing to one of the still-existant nodes.

It's a performance trade-off that works well when you're doing a lot of
list manipulations with few iterators per list, which I would assume is
a common case.

-- 
Darren New 
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