I don't really see anything but a superficial resemblance to rust, where both are borrowing ideas from the same place. Where Rust really differs from modern alg

I don't really see anything but a superficial resemblance to rust, where both are borrowing ideas from the same place. Where Rust really differs from modern algol-family-languages-learning-from-30-year-old-functional-programming-research is in its strictness. The optional type stuff is good, and it will definitely be a net safety improvement, but it's by no means attempting to approach a panacea to safety like Rust's strict static analysis does. Particularly that Swift gives you really simple outs in the form of the '!' unwrap and 'as' (should be 'as!' at least imo) downcast-and-unwrap operators that result in run-time errors and will probably be seen as unremoveable code-smell in a couple of years.