[phobos] Fwd: Re: Ruling out arbitrary cost copy construction?

[Max Samukha]

On Tue, Nov 2, 2010 at 8:08 PM, Steve Schveighoffer <schveiguy at yahoo.com>wrote:

> All of these have nothing to do with sealed ranges.  They have to do with
> data
> lifetime.  If you destroy data and then try to access it, you will have
> problems
> with or without sealed ranges.  In addition, only one instance you show has
> a
> sealed range in it.  The rest either don't have ranges or are not sealed.
>
> Having a sealed range does not necessarily mean that the user cannot shoot
> themselves in the foot and delete the data while still maintaining
> references to
> it.  This problem is mostly solved by having the data or at least the
> pointer to
> the data on the heap, destroyed by the GC when no longer needed.
>
> Even then, this does not rule out the user calling clear on the pointer.
>
> SealedRange is not a magic bullet for memory issues, and all these issues
> exist
> with or without sealed ranges or expensive copy construction.
>
> What SealedRange *does* do is allow the container to have complete control
> over
> the storage for the data.  This means it can:
>
> a) intercept all accesses to the memory, including writes and reads.
> b) use abstracted allocation schemes.
>
> -Steve
>
>
>
> ----- Original Message ----
> > From: SHOO <zan77137 at nifty.com>
> > Another viewpoint.
> >
> > Is  SealedRange really appropriate?
> >
> > All these are caused by the same  problem:
> > - http://ideone.com/x1Zus
> > - http://ideone.com/iM18Q
> > -  http://ideone.com/TTin3
> > - http://ideone.com/x4b0o
> >
> > We should consider  that we grope the common solution for these problems.
> > It is the method that  block the access to reference data of which
> > instance was  deleted.
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>
>
>
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