Chapter 10: Enums and Pattern Matching

In this chapter, we explore one of Rust’s most powerful features: enums. Rust’s enums go beyond what C provides by combining the capabilities of both C’s enums and unions. They allow you to define a type by enumerating its possible variants, which can be as simple as symbolic names or as complex as nested data structures. In some languages and theoretical texts, these are known as algebraic data types, sum types, or tagged unions, similar to constructs in Haskell, OCaml, and Swift.

We’ll see how Rust enums improve upon plain integer constants and how they help create robust, type-safe code. We’ll also examine pattern matching, a crucial tool for handling enums concisely and expressively.