Re: [boost] [interprocess] preparing containers

Subject: Re: [boost] [interprocess] preparing containers
From: Thorsten Ottosen (thorsten.ottosen_at_[hidden])
Date: 2008-12-03 04:17:34

Ion Gaztañaga skrev:
> Thorsten Ottosen wrote:
[snip]
>> In particular, if I want to use boost::ptr_vector, then do I need to 
>> have stateful allocators (both the normal container allocator, and the 
>> clone_allocator)?
> 
> Sorry, I'm not familiar with ptr_containers. If you can give me some 
> hints on what's clone_allocator for, I'll be glad to help you to make 
> ptr_container compatible with shared memory allocators. Just one issue: 
> shared memory does not support virtual functions, so I don't think 
> polymorphic cloning will be usable at all.

Currently the clone-allocators are a stateless customization point for 
cloning. It tells the containers how to clone the (indirectly) held 
pointees.

I guess support for virtual functions is needed, except for the most 
trivial cases. So what does it mean exactly, that shared memory does not
support virtual functions? Can I never call a virtual function on an 
object if that object's memory is shared? (In which case I'm a bit 
puzzled :-))

-Thorsten