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)

Summary

In this chapter, we covered the metaprogramming abilities of Rust and looked at many kinds of macros. The most frequently used macro is macro_rules!, which is a declarative macro. Declarative macros work at the abstract syntax tree level, which means that they do not support arbitrary expansions, but require that the macro expansions are well-formed in the AST. For more complex use cases, you can use procedural macros where you get complete control of manipulating the input and generating the desired code. We also looked at ways to debug macros using the cargo subcommand cargo-expand.

Macros are indeed a powerful tool, but not something that should be used heavily. Only when the more usual mechanisms of abstraction such as functions, traits, and generics do not suffice for the problem at hand should we turn to macros. Also, macros make the code less readable for newcomers...