DIP69 - Implement scope for escape proof references

[Martin Nowak via Digitalmars-d]

On Thursday, 4 December 2014 at 09:25:11 UTC, Walter Bright wrote:
> http://wiki.dlang.org/DIP69
>
Great stuff.

Will this be possible, it's a fairly important use-case.

scope ref T setVal(scope ref T t)
{
     t.val = 12;
     return t;
}

Another question, how would a reference counted pointer take 
advantage of scope, i.e. avoid the increment/decrement when being 
passed to a function?
One solution would be to add a function that returns a scoped 
reference to the underlying value.
     struct RefCounted(T)
     {
         scope ref T borrow() { return *p; }
     }
Will it be possible to deduce, that the lifetime of that scoped 
value is tied to the smart pointer?