Re: [boost] Heads up - string_ref landing

Subject: Re: [boost] Heads up - string_ref landing
From: Gottlob Frege (gottlobfrege_at_[hidden])
Date: 2012-12-13 12:05:20

On Thu, Dec 13, 2012 at 5:20 AM, Rob Stewart <robertstewart_at_[hidden]>wrote:

> >>
> >> It is the logical interpretation. It indicates whether the string is
> >> non-empty. I don't see any other generally useful interpretation, do
> you?
> >
> > Qt's QString has both empty() and isNull() and they are not always the
> same.  Basically empty() is a zero-byte string, but null is a
> > never-been-set-or-allocated string.
> [snip]
>
> > Somewhat like optional<string>.
>
> That's how I'd spell it.

Me too maybe.  But either way, there is another 'generally useful
interpretation'.  And fairly well known.

For string_ref, it could mean the difference between these 2 string_refs,
assuming a ptr+size implementation:

{ ptr != 0,  size == 0 } and { ptr == 0, size == hopefully_zero }