RE: [boost] Re: Conversion from auto_ptr to scoped_ptr?

From: Victor A. Wagner, Jr. (vawjr_at_[hidden])
Date: 2002-06-17 21:48:53

I'm puzzled.  Why does this create a dependency on auto_ptr<> ?
At Monday 2002/06/17 14:57, you wrote:

> > From: Markus Schöpflin 
> [<mailto:markus.schoepflin_at_[hidden]>mailto:markus.schoepflin_at_[hidden]] 
>
>[snip]
> > Hmm, I did some further thinking on this and I simply can't see the
> > difference between the current shared_ptr, which offers a
> > conversion from
> > auto_ptr and my suggestion for scoped_ptr.
> >
> > Could you enlighten me, Peter? Or anybody else?
> >
>
>I'd argue that introducing a dependency to std::auto_ptr is not in the 
>best interest of scoped_ptr. It seems to me that scoped_ptr differs from 
>shared_ptr in design intent - scoped_ptr should know and require as little 
>as possible (but no less), whereas shared_ptr takes pride in being smart.
>
>There are two idioms that can be used to approximate scoped_ptr in the 
>scenario where an auto_ptr is returned from a function:
>
>0) Declare the auto_ptr const. This comes very close to the behavior of 
>scoped_ptr, with the exception that you can reset the scoped_ptr, but not 
>the auto_ptr.
>
>1) Use solution 0 together with scope (pun intended): { const 
>std::auto_ptr... }. This takes care of most cases where the pointee must 
>be deleted at a certain location in the code.
>
>Armed with these tools, the most compelling argument that remains for 
>adding the conversion from auto_ptr to scoped_ptr is stating the intent of 
>code more clearly; but does the added value really outweigh the cost of 
>the added dependency?
>
>Bjorn

Victor A. Wagner Jr.      http://rudbek.com
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