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From: Gavin Collings (gcollings_at_[hidden])
Date: 2000-01-28 12:16:58

> I think I discovered a new approach for smart pointers (tell me if
> this has been done). Instead of maintaining the reference count as
> an integer created on the heap, the smart ptr objects internally
> maintain a double-linked list in which they are members.

I have this implemented as a template with minor differences: -

- I set the "unique" pointer values to point to self to avoid null
- I think there's a bug in your swap function - you need to adjust the
back pointer in other objects to reflect that this now collaborates
with a different set of smart pointers.

- I have the list pointers as mutable to reflect the fact that they may
be changed by other objects.

I've done timing tests which agree with yours, I also tried to
characterize the speed advantage against set size and found that
there's a cross over at about 25-50 members -i.e. the current
implementation becomes more efficient when greater than that number
share a single pointer.

There is also an additional benefit of better exception guarantees.
I'm all for it.


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