State Machine

Rust enums are far more than a set of constants. They carry data, drive state machines, replace null, and unify error handling. This guide walks you from basics to recursive enums with real code examples.

A practical deep dive into Rust async: why calling an async function doesn’t run it, how the compiler turns async into a state machine, and how executors drive tasks forward with poll and Waker. Understand the real mechanics behind async/await.