The following code is almost exact replica from Apple Documentation and compiles without errors: guard let firstItem = (rawItems! as? Array<Dictionary<String, Any>>)?.first else { thr...

I am looking for an idiomatic solution to this problem. I am building a val Scala (immutable) Map and would like to optionally add one or more items: val aMap = Map(key1 -> value1, key2 -&gt...

I know the definition for a single exclamation mark, but two? I was coding today and the compiler "force" me to add one more ! to my sentence: mySignal.subscribeNext({ (value: AnyObject!) -> ...

I'm trying to make a simple if-let statement with more than one value. The if block should be executed only if all optional vars are non-nil, plus they should be assigned to the new let-vars (const...

I want to do something like foo[OptionsPattern[]] := OptionValue[b] Options[foo] = {a -> 0, b :> OptionValue[a]}; foo[a -> 1] and have Mathematica give me 1, instead of 0. Is there a be...