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Subject: Re: [boost] scoped_ptr deleter
From: Stefan Strasser (strasser_at_[hidden])
Date: 2009-09-16 12:08:16

Am Wednesday 16 September 2009 16:01:00 schrieb Felipe Magno de Almeida:
> On Wed, Sep 16, 2009 at 12:54 PM, Stefan Strasser
> <strasser_at_[hidden]> wrote:
> > Am Wednesday 16 September 2009 10:34:35 schrieb Berserker:
> >> Dmitry Goncharov wrote:
> >>  > The difficulty that your example demonstrates is caused by the nature
> >>  > of template template parameters. scoped_ptr should not be blamed for
> >>
> >> that.
> >>
> >> I agree, moreover I think that the advantages of this patch (often
> >> required in the list)
> >
> > could you explain what those advantages are?
> > a scoped_ptr can't be copied at can't be moved. so there are two use
> > cases left for a scoped_ptr deleter:
> >
> >  - scoped_ptr as a class member: execute code when the class gets
> > destructed -> that's what a destructor is for.
> You could say the same for use delete in the destructor and never use
> scoped_ptr at all.

the point of a deleter is to execute CUSTOM code at destruction.
using scoped_ptr (without deleter) automates deletion so you don't have to
write custom code that does that. that simplifies things a lot.
but a scoped_ptr delete would provide the same thing as a destructor or a
scope exit: execute custom code.
the only reason shared_ptr or unique_ptr do have deleters is because the point
of destruction aren't statically known, as they can be copied or moved.

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