which is why I carefully used the word Naive, however I had little time to expand on it so I can't blame anyone for overlooking that.

> If you're only borrowing the value...

Then you give examples of manually offloading memory management to the programmer. It should be done, and I believe the book I reference covers it (can't find it now, sorry), but definitely not by the programmer else it's not automatic GC.

> ARC is usually atomic reference counting.

That won't make any necessary inter-core or inter-socket coherency traffic disappear.

> Any heap allocations [...] is likely to cause memory fragmentation.

My memory was that refcounting was particularly bad but feel free to disregard that as I can't justify it. I may well be wrong.

> This is a "can submarines swim" type of question and is completely uninteresting (imo).

eh? Puzzled...

> it doesn't.

thanks, will check.