Summary

In this chapter, we covered changes to the Foundation framework. We started with a discussion on mutability and new value types in Foundation. You learned that both value and reference types have their place in our code. Next, we covered nested enumerations and strongly typed string enumerations. We explored class properties and the type-safe access benefits of value types. Finally, we spent a great deal of time discussing the new Measurements API introduced this year in Foundation. In the next chapter, we will cover testing and debugging. Swift 3 introduces several changes in testing and debugging that should help improve the quality of the code you write.