Hands-On Design Patterns with Swift

Leveraging the prototype pattern

If you're using value types, you will not find yourself needing to implement the prototype pattern, as value types implement copy-on-write.

Let's use our Article object from the previous example again, but this time as a class, so we don't benefit from the copy-on-write given by the value types:

class Article {    private(set) var id: String    let title: String    let message: String    let author: String    let date: Date    var views: Int    init(id: String,         title: String,         message: String,         author: String,         date: Date,         views: Int) {        self.id = id        self.title = title        self.message = message        self.author = author        self.date = date        self.views = views    }}

Now we have Article following reference-type semantics, and we needed to add a constructor. ...