Book Image

Rust Programming By Example

By : Guillaume Gomez, Antoni Boucher
Book Image

Rust Programming By Example

By: Guillaume Gomez, Antoni Boucher

Overview of this book

Rust is an open source, safe, concurrent, practical language created by Mozilla. It runs blazingly fast, prevents segfaults, and guarantees safety. This book gets you started with essential software development by guiding you through the different aspects of Rust programming. With this approach, you can bridge the gap between learning and implementing immediately. Beginning with an introduction to Rust, you’ll learn the basic aspects such as its syntax, data types, functions, generics, control flows, and more. After this, you’ll jump straight into building your first project, a Tetris game. Next you’ll build a graphical music player and work with fast, reliable networking software using Tokio, the scalable and productive asynchronous IO Rust library. Over the course of this book, you’ll explore various features of Rust Programming including its SDL features, event loop, File I/O, and the famous GTK+ widget toolkit. Through these projects, you’ll see how well Rust performs in terms of concurrency—including parallelism, reliability, improved performance, generics, macros, and thread safety. We’ll also cover some asynchronous and reactive programming aspects of Rust. By the end of the book, you’ll be comfortable building various real-world applications in Rust.
Table of Contents (18 chapters)
Title Page
Copyright and Credits
Packt Upsell
Events and Basic Game Mechanisms

Creating functions

We had a brief introduction to functions when we saw the main function. Let's see how to create functions with parameters and a return value.

Here's how to write a function that returns the maximum of two numbers:

fn max(a: i32, b: i32) -> i32 {
    if a > b {
    } else {

The parameters are between parentheses and must be explicitly typed since the type inference only infers the types of local variables. This is a good thing since this acts as a documentation. Moreover, this can prevent bugs when we change how we use the parameters or change the value that is returned. The function can be defined after it is used without any issue. The return type is after ->. When we return (), we can omit the -> and type.

The last expression in the body of a function is the value returned from the function. You don't need to use return. The return keyword is only needed when you want to return early.