Re: [Boost-users] seeking comments on 'weak_key_map' experiments

Subject: Re: [Boost-users] seeking comments on 'weak_key_map' experiments
From: Frank Mori Hess (frank.hess_at_[hidden])
Date: 2008-12-12 11:52:23

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On Friday 12 December 2008 10:11 am, Nicolas Lelong wrote:
> > Is there some way that this can interface with boost::shared_ptr/weak_ptr
> > better? weak_key_map<int, int> m;
> > boost::shared_ptr<int> k(new int(1));
> > m.insert(std::make_pair(k,5));
> >
> > assert(*m.find(k) == 5);
> >
> > k.reset();
> >
> > assert(m.empty());
>
> I'd also like that, but in this approach, I can't figure how to hook into
> the key shared_ptr deleter to have access to a notification of the
> smart_ptr deletion. I think we can currently get the current deleter of a
> shared_ptr, but we can't change it to combine it with another deleter.

Does the weak_ptr need to be removed from the map "instantly" when it expires?  
Could you just clean up the expired weak_ptrs at some later point?  For 
example, when an iterator is incremented it might remove all the weak_ptrs it 
encounters while it is trying to find the next live weak_ptr in the map.
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