Re: [boost] [review][pimpl_ptr] Pimpl Pointer review (COW)

From: Tobias Schwinger (tschwinger_at_[hidden])
Date: 2006-05-20 07:42:54

Rene Rivera wrote:
> I think we all have to keep in mind the scope of this utility. It not 
> meant to solve all the pointer uses. 

I understand your concern, still, in my eyes COW is just another 
application of the handle/body pattern and thus not /that/ far 
away from the scope of this submission. 

> There's another utility that people keep asking for, the traits pointer.

Whether a single policy-based can-do-whatever-pointer is really 
what we want is a different story.

>>>
>>>It seems like you assume that two pimpl_ptr instances can hold the same
>>>pointer. This is _not_ the case. 
>>
>>Why not?
> 
>  From my experience, you don't because at that point you would use some 
> other kind of pointer. Most likely a reference counted pointer that can 
> travel across DLL boundaries.

<cite>
    However, it's implementation can be tricky, and with many pitfalls 
    (especially regarding memory management).
</cite>

    template<typename T> void dispose_func(void* ptr) 
    { delete static_cast<T*>(ptr); }
    // use void(*)(void*) to this thing for freeing the shared context
    // and the instance

Regards,

Tobias