Weakrefs require “careful programming” i.e. knowing which ref must be a weakref. By “cheating” I don’t mean “unsafe” but all kinds of pointers that aren’t just

Weakrefs require “careful programming” i.e. knowing which ref must be a weakref. By “cheating” I don’t mean “unsafe” but all kinds of pointers that aren’t just unique or borrowed such as different reference-counted pointers, the existence and use of which demonstrates that ownership+borrowing isn’t a complete memory-management technique. You need reference counting, therefore you need GC or careful programming. Hopefully we discover some technology that makes these needs go away, but not so far AFAIK.