[boost] How To Declare Enumerators (was: IOStreams formal review start)

From: Jonathan Turkanis (technews_at_[hidden])
Date: 2004-09-10 16:41:23

"Rob Stewart" <stewart_at_[hidden]> wrote in message:
> From: "Jonathan Turkanis" <technews_at_[hidden]>
> > "Rob Stewart" <stewart_at_[hidden]> wrote in message:
> > > From: "Jonathan Turkanis" <technews_at_[hidden]>

> > I stole this idiom from John Maddock: http://tinyurl.com/4no5s. It's
supposed to
> > make insertion in the middle easier. I think it's the vector vs. list
tradeoff.
>
> It fails to make insertion in the middle easy, at least
> comparatively.  Start with:
>
>    Yours/John's            Mine
> enum
> {
>    name_a = 1,             1<<0,
>    name_b = name_a << 1,   1<<1,
>    name_c = name_b << 1    1<<2
> };
>
> Now add name_x after name_b:
>
> enum
> {
>    name_a = 1,             1<<0,
>    name_b = name_a << 1,   1<<1,
>    name_x = name_b << 1,   1<<2,
>    name_c = name_x << 1    1<<3
> };
>
> Your version requires a more extensive change

True -- if there are only three enumerators!

> due to the use of
> the enumerator name and makes it harder to determine if the new
> order is, in fact, sequential.

Also true.

Best Regards,
Jonathan