Book Image

Rust Essentials - Second Edition

By : Ivo Balbaert
Book Image

Rust Essentials - Second Edition

By: Ivo Balbaert

Overview of this book

Rust is the new, open source, fast, and safe systems programming language for the 21st century, developed at Mozilla Research, and with a steadily growing community. It was created to solve the dilemma between high-level, slow code with minimal control over the system, and low-level, fast code with maximum system control. It is no longer necessary to learn C/C++ to develop resource intensive and low-level systems applications. This book will give you a head start to solve systems programming and application tasks with Rust. We start off with an argumentation of Rust's unique place in today's landscape of programming languages. You'll install Rust and learn how to work with its package manager Cargo. The various concepts are introduced step by step: variables, types, functions, and control structures to lay the groundwork. Then we explore more structured data such as strings, arrays, and enums, and you’ll see how pattern matching works. Throughout all this, we stress the unique ways of reasoning that the Rust compiler uses to produce safe code. Next we look at Rust's specific way of error handling, and the overall importance of traits in Rust code. The pillar of memory safety is treated in depth as we explore the various pointer kinds. Next, you’ll see how macros can simplify code generation, and how to compose bigger projects with modules and crates. Finally, you’ll discover how we can write safe concurrent code in Rust and interface with C programs, get a view of the Rust ecosystem, and explore the use of the standard library.
Table of Contents (13 chapters)

Associated functions on structs


Rust makes it possible to call a method in two ways. For example, when we want to obtain the length of a string, you can do:

// see code in Chapter 6/code/paradigm.rs 
let str1 = "abc"; 
println!("{}", str::len(str1)); // 3 
println!("{}", str1.len());     // 3 

The first way is procedural and calls the len function from the str crate in the standard library and passes the string slice str1 as a parameter. The second way which is more object-oriented and more commonly used calls the len method on the string slice str1. If you look it up in the API docs, you can see it has the signature:

   fn len(&self) -> usize 

It effectively takes a reference (&) to self as a parameter.

So we see that Rust caters also for more object-oriented developers, who are used to the object.method() type of notation instead of function(object) type of notation. In Rust, we can define associated functions and methods on a struct, which pretty much compares to the traditional...