[swift-evolution] [Proposal] Add an API to Unmanaged to get the instance it holds "@guaranteed"

[Dave Abrahams]

on Mon Mar 14 2016, John McCall <rjmccall-AT-apple.com> wrote:

>> In this example this would be for the lifetime for the value in x which extends to the lifetime of y.
>
> What if I return it or assign it to non-local memory?
>
> I feel like you’re trying to define this by optimizer behavior.
> That’s not a workable language rule; programmers are not going to
> reason about SSA values.

Thank you, John.  That is the problem I usually have with evaluating
most optimizer proposals.

-- 
-Dave