From: Daniel James (daniel_at_[hidden])
Date: 2005-04-03 15:02:46
Jaap Suter wrote:
> 1. Instead of providing the two options of deriving and embedding, let
> the user provide ADL-style 'next' and 'prev' lookup functions that for a
> given type provide hooks to the intrusive containers. Look at the
> boost::intrusive_ptr documentation for more information on this style.
> You can still provide the existing two methods as possible ways of
> providing these hooks, but if my legacy code (or for some other reason)
> has types with their own next and prev pointers, I still want to be able
> to use your code.
I'm not sure about this, most of the difficulty is involved in
manipulating the links - iterator adaptor or facade can be used to
easily create iterators for types with their own next and prev pointers.
> 2. As you mention, inserting an object twice leads to problems. In
> general, intrusive lists need to be handled with more care. I would like
> to see a diagnostics mode that checks invariants and preconditions.
> Things to check for would be checking if an instance doesn't already
> exist on inserts, and checking whether there are no loops in a list.
> Because this will make list-manipulation really slow, I'd like to be
> able to enable this on a per-instance basis, probably through
> boolean-ish or policy-based template parameters.
If there was a check that a node wasn't in a container on insertion
wouldn't these problems disappear?
Daniel