Gain insights into Rust programming fundamentals, explore its syntax, ownership, and type system, and delve into core components like memory management, traits, and generics to enhance your skills.

Rust is quickly becoming one of the most popular languages. With a strong basis as a systems and embedded language, its clean design and ergonomics makes it an emerging choice for general purpose programming tasks as well. This course will be your guide to the fundamentals of programming and Rust. Whether you have no experience or want to learn a new language, this is the place to start.

In this course, you’ll start off with the basics of the Rust programming language, learning the syntax, the philosophy of the language, and the anatomy of Rust. With that in hand, you’ll move onto some of the more unique parts of Rust, such as expression-oriented programming, ownership, and its strong type system.

In the latter half of the course, you’ll work through some of the core components of Rust such as references, memory management, mutability, traits, slices, and generics.

By the time you finish, you’ll have the foundations in place to learn more advanced concepts and take your Rust programming to the next level.

The Ultimate Guide to Rust Programming

Traits show up so much in Rust that we’ve already mentioned them multiple times in our previous lessons. It’s time to finally dive into this topic. We’ll start off with some simpler examples of traits. Then, we’ll get into some stronger motivation for using traits, focusing on some limitations we cleverly avoided with type parameters previously.

Let's say I want to write a function that can double both `i32`s and `i64`s. I’m going to start off by using the ugly "add the type to the name" approach and end up with two functions:

fn double_i32(x: i32) -> i32 {
    x * 2
}

fn double_i64(x: i64) -> i64 {
    x * 2
}

fn main() {
    println!("double 5_i32 == {}", double_i32(5_i32));
    println!("double 5_i64 == {}", double_i64(5_i64));
}


But I don’t like that at all\! This feels like something that would be much more pleasant if:

1.  I had the same name for both types

2.  I could use method syntax

So, let’s go ahead and try to write two `impl` blocks:

impl i32 {
    fn double(&self) -> Self {
        self * 2
    }
}

impl i64 {
    fn double(&self) -> Self {
        self * 2
    }
}

fn main() {
    println!("double 5_i32 == {}", 5_i32.double());
    println!("double 5_i64 == {}", 5_i64.double());
}


Unfortunately, this doesn’t work. And perhaps more unfortunately, the compiler’s error message about this is more confusing than helpful:

```text
error[E0390]: only a single inherent implementation marked with `#[lang = "i32"]` is allowed for the `i32` primitive
```

So, ignore the error message. I’m going to teach you a new rule: you can’t define `impl` blocks for types that are defined elsewhere. If you write a `struct`, you control it yourself, and you can add any methods to it. But if something comes from `std` (like `i32`, or `String`, or `Vec`), you’re not allowed to add methods to it.

But have no fear\! There’s still a way that you can add a method to a type, just not directly. And this is where we’ll first introduce *traits*. Traits introduce a set of functionality that isn’t tied to a specific type. Instead, it can be *implemented* for many different types. Our doubling concept is a great example, we can double an `i32`, or an `i64`, or even a `Fruit` value.

>**NOTE**: You may be wondering, why this limitation? We won’t get into these kinds of “why” questions here, but at the time of writing, there is [some material online](https://github.com/Ixrec/rust-orphan-rules) you can read regarding this if you’re curious.

Okay, let’s see what a trait definition looks like:


Welcome to Begin Rust

Hello World and variables

Anatomy of Rust

Functions

Booleans

Conditionals

Mutable variables and while loops

Structs and ownership

References

Methods

Strings

Arrays, Vecs, and slices

Type parameters

Traits

Enums

Iterators and for loops

Early exit

What’s next?

Double Double