Rustlings is a set of exercises that serves as a great introduction to the Rust language. It covers many concepts from the Rust book by asking you to work through sets of exercises.
This collection walks you through Rustlings in a way that explains what's going on in each exercise. We cover everything from basic types to generics and threading.

Syllabus

Setup Rustlings
Rustlings variables1: Running the rustlings CLI and completing exercises
Rustlings variables2: Declaring types and assigning values to variables
Rustlings variables3: Using the mut keyword to declare a mutable variable
Rustlings variables4: Initializing a variable with a value
Rustlings variables5: Using block scopes to shadow previously declared variables
Rustlings if1: Using an if/else statement to implicitly (or explicitly) return a value
Rustlings functions1: Declaring your first function
Rustlings functions2: Adding a type to function arguments
Rustlings functions3: Passing an argument to a function
Rustlings functions4: Declaring the return type of a function
Rustlings functions5: Implicitly returning values from functions
Rustlings test1: Writing a function that passes a set of tests by reading error messages
Rustlings primitive_types1: Introducing boolean values
Rustlings primitive_types2: String and Character literals using different quote styles
Rustlings primitive_types3: Create an array of numbers using Ranges
Rustlings primitive_types4: Referencing contiguous slices of data we don't own using range
Rustlings Primitive_types5: Destructuring values from a tuple
Rustlings primitive_types6: Accessing specific values in a tuple by index
Rustlings structs1: Instantiating Classic, Tuple, and Unit structs
Rustlings structs2: Filling in the unspecified fields in structs with update syntax
Rustlings strings1: String literals are string slices, not String structs
Rustlings strings2: String structs can be turned into &str slices via referencing
Rustlings test2: Determining when a value is a String struct vs a string slice
Rustlings enums1: Declaring enums
Rustlings enums2: Defining enum variants using classic, unit, and tuple structs
Rustlings enums3: Working with enums by pattern matching variants
Rustlings tests1: Introducing the assert! macro
Rustlings tests2: Introducing the assert_eq! macro
Rustlings tests3: Writing tests for a function
Rustlings test3: Testing a function multiple times
Rustlings modules1: Declaring public functions in a module using the pub keyword
Rustlings modules2: Defining public interfaces for nested modules
Rustlings macros1: Writing your first macro
Rustlings macros2: What order you write macro definitions in matters
Rustlings macros3: Exporting a macro from a module
Rustlings macros4: Using rustfmt to fix common syntax issues
Rustlings test4: Defining macros that accept arguments
Rustlings move_semantics1: Borrowing vectors as mutable
Rustlings move_semantics2: Fixing the borrow of moved values with cloning or references
Rustlings move_semantics3: Specifying that a function argument is mutable
Rustlings move_semantics4: Initializing a vector with the vec! macro
Rustlings errors1: Propagating the reason something failed using Result, Err, and Ok
Rustlings errors2: Handling errors by unwrapping or early-returning with the `?` operator
Rustlings errors3: Using the `?` operator in the main function
Rustlings errorsn: Using Box to dynamically return one of multiple error types at runtime
Rustlings option1: Introducing the Option type
Rustlings option2: Using if let and while let to process Optional values
Rustlings result1: Using custom enum variants as errors in Result return types
Rustlings clippy1: Using Clippy linting to discover potentially dangerous code scenarios
Rustlings clippy2: Making code more readable with clippy linter suggestions
Rustlings arc1: Using Arc to share data safely among threads
Rustlings iterators2: Introducing Iterators by manually calling .next and using .iter()
Rustlings iterators3: Iterating and collecting values using the IntoIter trait
Rustlings iterators4: Implementing Factorial with Iterators
Rustlings traits1: Extending a type with additional functionality by implementing traits
Rustlings traits2: Implementing a Trait for a Vector of Strings
Rustlings generics1: Using Vectors, a struct that implements generics
Rustlings generics2: Converting concrete types to generic implementations
Rustlings generics3: Constraining generics using traits