How to add an optional string extension?

Question

You can create a String extension like so:

extension String {
   func someFunc -> Bool { ... }
}

but what if you want it to apply to opt

Answer 1

In Swift 4.1 I was getting a Optional is ambiguous for type lookup in this context build error. To fix, you have to explicitly add the Swift namespace to the type:

extension Swift.Optional where Wrapped == String {
    var isBlank: Bool {
        return self?.isBlank ?? true
    }
}