My guess is that they will make this explicit in SIL first, to be able to add that into the language syntax later. For instance, as far as i know, the auto ref

My guess is that they will make this explicit in SIL first, to be able to add that into the language syntax later. For instance, as far as i know, the auto ref-counting model is on SIL, who injects lower level refcounting ops into the intermediate code, before going through the LLVM pipeline. This was a good thing to do, now that they are willing to open the ownership model to other kinds of ownership. Which will probably be controlled by the dev in the end. At least, that's what i understood from what i read. Its SIL only for now, but it means what is it implying it means. A opt-in manually controlled ownership model when ref-counting is not the best approach.