[Boost-users] Re: Using shared_ptr slightly different

From: Pablo Aguilar (pablo.aguilar_at_[hidden])
Date: 2005-04-11 13:45:10

"Daniel Lidström" <daniel.lidstrom_at_[hidden]> wrote in message 
news:E1F34343C3A0804BB3E29ABBFCBBAF0C01BCE3_at_ADA...
> Hello,
>
> I want to use the shared_ptr with objects that are allocated using
> a factory. The problem is the deallocation. It has to be done with
> a ``manager'' class. For example, here is how the allocation and
> deallocation has to be done:
>
> PxyFileData& geo_file = dynamic_cast<PxyFileData&>(fileMan.New("geo"));
> fileMan.Close(geo_file);
>
> I would like to be able to put shared_ptr<PxyFileData>'s into a 
> std::vector
> and then forget about the deallocation. I.e. fileMan.Close(...) should be
> done automatically when the objects aren't needed anymore. But since the
> deallocation isn't simply delete, how can I do this?
>
> Thanks!
>
> -- 
> Daniel
> SBG AB

If fileMan.Close received pointers, you could do the following:

shared_ptr<PxyFileData> ptr(
      &geo_file
    , boost::bind(
            boost::mem_fn(&<fileMan's type here>::Close)
        ,  &fileMan
        , _1
    )
);

If Close doesn't take pointers, I guess you could use Boost.Lambda's bind 
instead (to dereference _1, so you'd write *_1), but since I haven't used 
it, I can't say for sure, the syntax should be about the same I think...

HTH

Pablo Aguilar