Our Sister

[Marco Leise via Digitalmars-d]

Am Sat, 28 May 2016 14:15:45 +1000
schrieb Manu via Digitalmars-d <digitalmars-d at puremagic.com>:

> On 28 May 2016 at 10:16, Adam D. Ruppe via Digitalmars-d
> <digitalmars-d at puremagic.com> wrote:
> > On Friday, 27 May 2016 at 21:51:59 UTC, Seb wrote:  
> >>
> >> not if [] would be ref-counted too ;-)  
> >
> >
> > That would be kinda horrible. Right now, slicing is virtually free and
> > compatible with all kinds of backing schemes. If it became refcounted, it'd:
> >
> > 1) have to keep a pointer to the refcount structure with the slice, adding
> > memory cost  
> 
> This is only true for the owner. If we had 'scope', or something like
> it (ie, borrowing in rust lingo), then the fat slice wouldn't need to
> be passed around, it's only a burden on the top-level owner.
> 'scope' is consistently rejected, but it solves so many long-standing
> problems we have, and this reduction of 'fat'(/rc)-slices to normal
> slices is a particularly important one.

I second that thought. But I'd be ok with an unsafe slice and
making sure myself, that I don't keep a reference around. A
lot of functions only borrow data and can work on a naked
pointer/ref/slice, while the owner(s) have the smart pointer.
These can of course be converted to templates taking either
char[] or RCStr, but I think borrowing is cleaner when the
function in question doesn't care a bag of beans if the chars
it works on were allocated on the GC heap or reference counted.

-- 
Marco