Custom types: structs, classes, enums

In Swift, the power to define and manipulate custom types—such as structs, enums, and classes—is fundamental to building robust and efficient applications. This chapter dives into advanced techniques for defining and enhancing custom types, aimed at improving their functionality and efficiency in your applications. You'll explore how to make your types more expressive, such as by customizing their string representations or enabling initialization from literal values, which makes them as straightforward to use as built-in types.

We'll cover key strategies for balancing custom behavior with automated features, like preserving memberwise initializers while adding custom ones. Efficiency is another major focus, with techniques like implementing copy-on-write to manage memory effectively and ensuring types use only the necessary resources.

Additionally, you'll learn how to use enumerations for modeling complex data structures and managing instances with precision, such as through factory methods or by simplifying comparisons with automatic protocol conformance.

By mastering these techniques, you'll be able to create sophisticated, efficient custom types that leverage Swift's type system, enhancing both the performance and clarity of your code.