C interface provides a pointer and a length... wrap without copying?

[ketmar via Digitalmars-d-learn]

cy wrote:

> On Saturday, 11 March 2017 at 23:43:54 UTC, Nicholas Wilson wrote:
>> A string *is* a pointer length pair, an immutable(char)[].
>
> Yes, but surely there's some silly requirement, like that the pointer 
> must only ever point to garbage collected memory, or something?

why should it? a slice can point anywhere, and GC is smart enough to know 
what memory it owns and what it isn't. if you'll try to append something to 
non-GC-owned slice, GC will make a copy first. so the only requirement is: 
"don't use `~=` on it if you don't want to have a memory leak".