Welcome back to the exciting journey of learning Rust through design patterns! 🦀 You've mastered various creational patterns so far, and now it's time to put those skills into action with a real-world project: a banking system. In this module, you'll utilize these patterns to streamline and organize the creation of different components within the banking system. Let's dive into applying what we've learned and creating some robust Rust code!

Before diving deeper, let’s briefly revisit the creational patterns we'll employ:

1. Singleton Pattern: Guarantees a struct has only one instance, offering a global access point to it.
2. Factory Method Pattern: Defines an interface for object creation but lets enums or traits alter the type of objects to be created.
3. Abstract Factory Pattern: Establishes an interface for creating families of related or dependent objects without detailing their specific classes.
4. Builder Pattern: Disassociates the creation of a complex object from its representation, allowing for different object representations using the same construction process.

We will embrace these patterns to implement a logger, various account types, and account factories within our banking application.

Here's a sneak peek into what you'll be building in this module. You will create:

1. Logger with the Singleton Pattern: We'll implement a logging mechanism using LazyLock, ensuring only a single logger instance exists across the application.
2. Accounts using the Factory Method Pattern: Different account types (Savings and Current) will be instantiated using a factory method, leveraging Rust's enums and traits.
3. Account Factories using the Abstract Factory Pattern: Implement abstract factory interfaces for generating various types of account objects based on user requirements.
4. Code Integration: We'll integrate these patterns into a cohesive and functional banking system application.

Ready to start building? Let's dive into the practice section together!