[Pitch] Enum Case Inferencing

[cukr]

You don't need multithreading to make things complicated

Let's fix `if let` syntax

Here are some ways to make a variable nil after checking if it's not nil var _returnedAlready = false /// returns `.some` once, and then always `.none` func returnOnce() -> Int? { if _returnedAlready { return nil } else { _returnedAlready = true return 123 } } class C { var variable: Int? = 123 } let c = C() var global: Int? = 123 func unrelatedFunction() { c.variable = nil global = nil } /// This function takes `Int`. What happens if you pass …