Re: [boost] Stack-based vector container

Subject: Re: [boost] Stack-based vector container
From: Nevin Liber (nevin_at_[hidden])
Date: 2011-01-24 11:53:40

On 23 January 2011 19:36, Howard Hinnant <howard.hinnant_at_[hidden]> wrote:

>
> But if there are correctness issues, I think they trump speed issues.
>

+1.

1.  Does not compile.  StackVector can't be copied or moved.
> 2.  Compiles and does an element-by-element move on both move construction
> and move assignment.
> 3.  Compiles and does copies based on C++03 rules; no C++0x move semantics.
>

I would like to see them copyable (and probably moveable, but I haven't
thought that through yet).  While the need to copy these things is rare, it
still comes up.

Calling this StackVector is somewhat of a misnomer, as I'd like to be able
to use an object of that type as a member variable, and that aggregate may
or may not be on the stack.  This is one (but not the only) reason I want it
copyable, as types that aren't copyable are a pain to use as member
variables.

> >From reading this thread I get that people want StackVector to avoid heap
> allocations.  But I really have no idea how people want StackVector  to
> behave in situations such as the above.  And without a clear understanding
> of such desired behavior, it seems difficult to design.
>

1.  There are times I know the likely largest size of a container, above
which I am willing to pay an allocation cost.
2.  There are times I want to limit the maximum size of a container.

Note:  StackVector does not solve all combinations of (1) and (2), but its a
good start. :-)
-- 
 Nevin ":-)" Liber  <mailto:nevin_at_[hidden]>  [phone]