UITextField.TextContentType is an NSString that must be one of the values / constants from UITextContentType. UITextContentType could be an enum and UITextField.ContentType could take that.
Unfortunately TextContentType is inside UITextInputTraits protocol and there is no "easy" way to turn this into an enum. It requires a little more of brain. Will discuss this in our next iOS meeting. But I totally agree this should be an enum.
Good, but not trivial, idea. https://trello.com/c/dTeHjWnP
Moving out of current milestone.
Ups my bad, working on the enum <-> NSString conversion but the support of this inside protocols is for another day