Book Image

Mastering Rust - Second Edition

By : Rahul Sharma, Vesa Kaihlavirta
Book Image

Mastering Rust - Second Edition

By: Rahul Sharma, Vesa Kaihlavirta

Overview of this book

Rust is an empowering language that provides a rare combination of safety, speed, and zero-cost abstractions. Mastering Rust – Second Edition is filled with clear and simple explanations of the language features along with real-world examples, showing you how you can build robust, scalable, and reliable programs. This second edition of the book improves upon the previous one and touches on all aspects that make Rust a great language. We have included the features from latest Rust 2018 edition such as the new module system, the smarter compiler, helpful error messages, and the stable procedural macros. You’ll learn how Rust can be used for systems programming, network programming, and even on the web. You’ll also learn techniques such as writing memory-safe code, building idiomatic Rust libraries, writing efficient asynchronous networking code, and advanced macros. The book contains a mix of theory and hands-on tasks so you acquire the skills as well as the knowledge, and it also provides exercises to hammer the concepts in. After reading this book, you will be able to implement Rust for your enterprise projects, write better tests and documentation, design for performance, and write idiomatic Rust code.
Table of Contents (19 chapters)

Debugging macros

When developing complex macros, most of the time you need ways to analyze how your code expands to the inputs you gave to the macro. You can always use println! or panic! at the places you want to see the generated code, but it's a very crude way to debug it. There's are better way, though. The Rust community provides us with a subcommand called cargo-expand. This subcommand was developed by David Tonlay at https://github.com/dtolnay/cargo-expand, who is also the author of the syn and quote crates. This command internally calls the nightly compiler flag -Zunstable-options --pretty=expanded, but the design of the subcommand was done in such a way that it doesn't require you to manually switch to the nightly tool chain as it finds and switches to it automatically. To demonstrate this command, we'll take the example of our IntoMap derive macro...