// // DatabaseObject+Database.swift // Database // // Created by Brent Simmons on 9/13/17. // Copyright © 2017 Ranchero Software. All rights reserved. // import Foundation import RSDatabase import Data extension Array where Element == DatabaseObject { func asAuthors() -> Set? { let authors = Set(self.map { $0 as! Author }) return authors.isEmpty ? nil : authors } func asAttachments() -> Set? { let attachments = Set(self.map { $0 as! Attachment }) return attachments.isEmpty ? nil : attachments } }