Re: [boost] [cpo-proposal] presentation of the idea

Subject: Re: [boost] [cpo-proposal] presentation of the idea
From: Thorsten Ottosen (thorsten.ottosen_at_[hidden])
Date: 2013-08-20 05:23:55

On 20-08-2013 11:04, Rob Stewart wrote:
> On Aug 19, 2013, at 9:44 AM, Thorsten Ottosen
> <thorsten.ottosen_at_[hidden]> wrote:

>> Yes, at this level it is nice to take advantage of the memcopying
>> built into vector<char>.
>
> Here's the problem. Replicating the bits of and object isn't the same
> as copying it. Many classes store a this pointer or rely on a data
> member address as a unique key, etc. Copy constructors must run.

OK. :-) I was waiting for an expert to join the discussion.

> If the container manages the reallocations by noticing when it is
> about to occur, creates a new vector with greater capacity, clones
> each element into the new vector, destroys the elements in the old
> vector, then swaps the two vectors, it can work.

Yeah, ok. I guess there will a need for one or two virtual functions
in a base class after all. Copy-construction is one way, 
move-construction probably better.

> I should think a deque would be better as it doesn't require all of
> that work.

Well, if we had a deque with better control over the chuck size, then 
perhaps. But I doubt it's a good idea.

The container should of course have a reserve( unsigned words ) function
as well as an shrink_to_fit() such that reallocations/memory use can be 
minimized.

-Thorsten