Rust at the Limit

The four corners of Rust where ordinary intuition stops working.

Read online at cloudstreet-dev.github.io/Rust-at-the-Limit

About This Book

Async, lifetimes, Pin, higher-rank trait bounds, variance — the parts of Rust where the type system stops feeling helpful and starts feeling like an antagonist.

This book is for engineers who have already cleared the borrow checker and hit the next wall. The error messages are paragraphs long. The type system has opinions about variance that they don't share. Async functions silently impose constraints they didn't sign up for. Pin exists.

The book takes the reader into that territory deliberately, with a guide rather than a tutorial. Tone is direct, technical, occasionally sympathetic, never condescending.

Table of Contents

Part I: The Type System's Edges

• Past the Borrow Checker
• Lifetimes Are Not What You Think
• Variance
• Higher-Rank Trait Bounds

Part II: Async, From the Inside

• Async Internals
• Async and Lifetimes Collide
• Pin and Why It Has To Exist
• The Async Trait Problem

Part III: Survival

• Error Messages, Decoded
• Patterns That Work

Part IV: Disagreement

• When the Type System Is Right and You're Wrong
• When the Type System Is Wrong and You're Right

Building Locally

cargo install mdbook
mdbook serve --open

License

CC0 1.0 Universal — public domain dedication. Take it, fork it, ship it, claim it as your own. See LICENSE.