Rust Study Repository

A comprehensive collection of Rust examples covering fundamental concepts to advanced patterns. This repository has been modernized to use Rust 2021 edition with current best practices and idioms.

🚀 Getting Started

Prerequisites

• Rust: Version 1.75 or later (2021 edition)
• Install via rustup: curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Running Examples

Navigate to any example directory and run:

cd <example-folder>
cargo run

To build without running:

cargo build

---

📚 Learning Path

This repository is organized as a progressive learning curriculum. Follow the sections in order for the best learning experience.

🟢 Level 1: Fundamentals

1. hello_cargo

Your first Rust program using Cargo.

• Concepts: Project structure, Cargo basics
• Key Files: Cargo.toml, src/main.rs
• Run: cd hello_cargo && cargo run

2. constants

Understanding constants and their differences from variables.

• Concepts: const vs let, type annotations, numeric separators
• Learn: Constants must have explicit types and are immutable
• Example: const MAX_POINTS: u32 = 100_000;

3. data-types

Comprehensive overview of Rust's type system.

• Concepts: Integers (u8, i32, u64, etc.), floats, characters, strings
• Learn: Type inference, explicit type annotations, literals
• Example: Parsing strings to numbers, working with different numeric types

4. basic-mutations

Introduction to mutability in Rust.

• Concepts: mut keyword, mutable references
• Learn: Variables are immutable by default
• Example: Modifying values through mutable references

5. arrays-vectors

Fixed-size arrays vs dynamic vectors.

• Concepts: Arrays [T; N], Vectors Vec<T>
• Learn: Arrays are stack-allocated, vectors grow dynamically
• Example: Array initialization, vector operations (push, indexing)

---

🟡 Level 2: Ownership & Functions

6. mutations-functions

Passing data between functions: by value, reference, or mutable reference.

• Concepts: Borrowing, ownership transfer, &str vs &String
• Learn: Ownership moves, borrowing rules
• Example: Functions that borrow vs consume values

7. match-some-err-options-results

Error handling and optional values the Rust way.

• Concepts: Option<T>, Result<T, E>, pattern matching
• Learn: match, if let, unwrap(), unwrap_or()
• Example: Handling None cases, error propagation with ?

---

🟠 Level 3: Intermediate Concepts

8. trait-struct-impl

Defining types and behaviors with structs and traits.

• Concepts: Structs, traits (interfaces), implementations
• Learn: Methods vs associated functions, trait bounds
• Example: Person trait implemented for Man struct

9. implementables

Implementing standard library traits for custom types.

• Concepts: Operator overloading with AddAssign, DivAssign
• Learn: How to make custom types work with operators like +=
• Example: Custom Count type with arithmetic operations

10. dereference

Understanding the dereference operator and smart pointers.

• Concepts: Deref, DerefMut traits, the * operator
• Learn: Deref coercion, mutable dereferencing
• Example: Creating smart pointer-like types

11. visitor-pattern

Design patterns in Rust: the Visitor pattern.

• Concepts: Design patterns, trait objects (dyn Trait)
• Learn: Separating data structures from operations
• Example: Animal structs with pluggable sound behaviors

---

🔴 Level 4: Advanced Features

12. closures-into-traits

Closures as function arguments with generic trait bounds.

• Concepts: Closures, Fn trait, generics, caching/memoization
• Learn: Using closures for expensive operations, result caching
• Example: Search cacher with closure-based file operations

13. cashier-macro

Declarative macros for code generation.

• Concepts: macro_rules!, repetition patterns, compile-time code generation
• Learn: When and how to write macros
• Example: Cashier calculator macro with variable arguments

---

🚀 Level 5: Web Development

14. parking-api

RESTful API using Rocket web framework (v0.5, async/await).

• Concepts: HTTP routes, JSON serialization, async handlers
• Learn: Building REST APIs with Rocket
• Example: CRUD operations for parking management
• Run: cd parking-api && cargo run, then visit http://127.0.0.1:8000

15. graphql-juniper-mongo

GraphQL API with MongoDB database integration (modern async).

• Concepts: GraphQL, async/await, database operations, error handling
• Learn: Modern async Rust, MongoDB driver, Juniper GraphQL
• Dependencies: MongoDB running on localhost:27017
• Example: Product CRUD via GraphQL
• Run: cd graphql-juniper-mongo && cargo run, then visit http://127.0.0.1:3030

---

🛠️ Key Rust Concepts Covered

Concept	Examples
Ownership & Borrowing	mutations-functions, basic-mutations
Error Handling	match-some-err-options-results
Traits & Generics	trait-struct-impl, closures-into-traits
Pattern Matching	match-some-err-options-results, visitor-pattern
Macros	cashier-macro
Async Programming	parking-api, graphql-juniper-mongo
Web Development	parking-api, graphql-juniper-mongo

---

📖 Additional Resources

• The Rust Book: doc.rust-lang.org/book
• Rust by Example: doc.rust-lang.org/rust-by-example
• Rust Standard Library: doc.rust-lang.org/std
• Cargo Book: doc.rust-lang.org/cargo

---

🔧 Modern Updates (2024)

This repository was originally created in 2019 (Rust 2018 edition) and has been modernized:

• ✅ Updated to Rust 2021 edition
• ✅ Removed deprecated extern crate declarations
• ✅ Applied modern idioms and best practices
• ✅ Updated dependencies to latest stable versions
• ✅ Replaced failure with anyhow/thiserror
• ✅ Modernized web frameworks (Rocket 0.5, async MongoDB driver)
• ✅ Added comprehensive documentation

---

🤝 Contributing

Feel free to open issues or pull requests to improve examples or add new ones!

📝 License

Educational purposes - feel free to use and modify.

---

Happy Learning! 🦀