# Tweet by [@keefmoon](http://twitter.com/keefmoon) on 2016-06-19 16:42:11 > [!INFO] Archived from [original tweet](http://twitter.com/keefmoon/status/744570986587131904) RT @NatashaTheRobot: Use a struct instead of a string as your dictionary key for better performance 💪 #swiftlang #WWDC16 https://t.co/9ITOL…