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 3.1 you can add an extension to optional values as well:

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