[boost] Re: variant questions

From: Eric Friedman (ebf_at_[hidden])
Date: 2003-08-30 17:40:37

David Abrahams wrote:
[snip]
> What does
>
>    Minimum strong exception-safety guarantee with respect to container
>    state for all operations.
>
> "with respect to container state" mean?

This is an admittedly muddled attempt at describing the exception safety
specification I described in my previous message. I'll certainly work on
clarifying this before release, but first I'd like that we all agree what
the exception safety specification should be (cf. other messages in thread).

> What does
>
>
>    Efficient, stack-based implementation.
>               ^^^^^^^^^^^
>
> This mean?
> I can guess that it means variant doesn't use dynamic allocation, but
> that's not always true is it?

Currently, it *is* always true for nonrecursive applications of variant
(i.e., all uses of variant not involving boost::recursive_variant or
boost::incomlpete).

For recursive applications though, heap allocation is usually involved.
Again, I understand I need to do more with the docs to make this point
clear.

Again, this may change if variant ultimately adopts your
'dynamically-allocated backup' proposal. Of course, the final semantics will
be described in the docs.

Thanks,
Eric