Re: [boost] [interprocess] [shared_ptr] Failure to type convert offset_ptr<T> to T *

From: Ion Gaztañaga (igaztanaga_at_[hidden])
Date: 2008-03-27 12:36:23

Aleksey Midenkov wrote:
> The failure is in sp_counted_impl.hpp:66:
> 
> 64     template<class Ptr>
> 65     sp_counted_impl_pd(const Ptr & p, const A &a, const D &d )
> 66        :  this_allocator(a), D(d), m_ptr(p.get())
> 67     {}
> 
> 
> p is of type offset_ptr<T> and m_ptr is of type T *
> 
> Test case source, compiler output and quick fix patch (which is not fully 
> correct, I suspect) are attached.

If you want to place the a shared_ptr in shared memory you must define a 
deleter whose pointer type is offset_ptr because otherwise, that 
shared_ptr can't be shared between processes if they map the memory in 
different address. You should define the deleter storing a shared_ptr.

Anyway, I think you are using quite an old Interprocess version, because 
shared_segment_deleter does not exist currently.

Download a up-to-date version from Boost SVN or the Boost 1.35 release 
candidate 2. Here's a link to the documentation about shared_ptr:

http://igaztanaga.drivehq.com/interprocess/interprocess/interprocess_smart_ptr/shared_ptr.html

Regards,

Ion