On 5/13/2014 10:52 AM, Dicebot wrote:
It has to be transitive to be useful as borrowed pointer. Consider this example:{ scope A a; // has some internally managed resources foo(a); } It is not safe to destruct a in the end of the scope here because foo may have stored references to a owned resources. But if foo signature is `foo(scope ref A a)` then compiler can statically verify that it is safe which is the very point of borrowing guarantees. It must be transitive to guarantee anything of course.
If those internal resources of A are marked as refcounted, then transitivity is not necessary. Consider also that a struct A can completely control any escaping references - transitive borrowing is not necessary.
