https://gist.github.com/lattner/31ed37682ef1576b16bca1432ea9...

Speaking of reliable systems, introducing an actor model is a good opportunity and excuse to introduce a mechanism for handling and partially recovering from runtime failures (like failed force-unwrap operations, out-of-bounds array accesses, etc). We explore several options that are possible to implement and make a recommendation that we think will be a good for UI and server applications.

This looks like a more principled approach that we will eventually get in Swift.