Book Image

Rust Standard Library Cookbook

By : Jan Hohenheim, Daniel Durante
Book Image

Rust Standard Library Cookbook

By: Jan Hohenheim, Daniel Durante

Overview of this book

Mozilla’s Rust is gaining much attention with amazing features and a powerful library. This book will take you through varied recipes to teach you how to leverage the Standard library to implement efficient solutions. The book begins with a brief look at the basic modules of the Standard library and collections. From here, the recipes will cover packages that support file/directory handling and interaction through parsing. You will learn about packages related to advanced data structures, error handling, and networking. You will also learn to work with futures and experimental nightly features. The book also covers the most relevant external crates in Rust. By the end of the book, you will be proficient at using the Rust Standard library.
Table of Contents (12 chapters)

How it works...

By invoking the lazy_static! macro [10, 21 and 29], we define a lazily initialized object in the current scope. Lazy here means created only the first time it is used.

Contrary to a let binding, its scope can also be the global scope [10]. A realistic example for this is creating a collection with a known content that is used by many functions, as the alternative would be to create it once and pass it around endlessly.

If your lazy_static consists of a Vec with content that is known at compile time, you can instead use a const array, as its construction is constant. In terms of code, this means you don't need to use this:
static ref FOO: Vec<&'static str> = vec!["a", "b", "c"];
Instead, you can use the following:
const FOO: [&str; 3] = ["a", "b", "c"];

Remember when, in Chapter 1, Learning the Basics; Querying with Regexes, we talked about how compiling Regexes is...