Copy Properties in Swift

copy.swift

import Foundation

class C {
    @NSCopying var copiedName: NSString?
    var noCopyName: NSString?
}

let f = NSMutableString(string: "First")

let obj = C()
obj.copiedName = f
obj.noCopyName = f

obj.copiedName // "First"
obj.noCopyName // "First"

f.append(" Last")

obj.copiedName // "First"
obj.noCopyName // "First Last"