Re: List container strawman 1.3

[Simon Wright <simon.j.wright@amsjv.com>]

John English <je@brighton.ac.uk> writes:

> Why does the iterator type need to be controlled? What's your mental
> model of what an iterator consists of? Mine generally says that an
> iterator contains a couple of pointers to a list somewhere else, but
> that the iterators aren't responsible for deallocating that
> list... is this something caused by the safe iterator requirement
> perhaps? (Which I disagree with, incidentally... safe iterators can
> probably be built on top of unsafe ones, but starting with safe ones
> means a lot of possibly unnecessary overhead.)

The BC Iterators are controlled so that creating an Iterator _can_
Lock the container it's iterating over, and deleting the Iterator (by
exiting the scope) will Unlock.

That said, the implication is that only one Iterator can be active for
a given container at any one time. Actually using such a beast is
going to be tricky, I think.

The C++ BCs didn't address this problem as far as I can see (there are
no substantive comments in the source ..)

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Simon Wright                         Email: simon.j.wright@amsjv.com
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