Differentiate between structs and enums in Rust, providing use cases for each.

In Rust, both structs (structures) and enums (enumerations) are essential data structures that serve distinct purposes in programming, contributing to the language's versatility and expressiveness. Let's explore the differences between structs and enums, along with use cases for each.

Structs (Structures):

1. Definition:
- A struct is a composite data type that allows you to group variables of different types under a single name.
- Fields in a struct are named and have specific types, providing a way to organize and represent related pieces of data.

2. Example:
```rust
struct Point {
x: f64,
y: f64,
}
```

3. Use Cases:
- Representing Objects:
- Structs are often used to model real-world objects by encapsulating related data fields.
- For example, a `Person` struct may include fields such as `name`, `age`, and `address`.

- Data Organization:
- Structs are useful for organizing and grouping data with different types into a single, cohesive unit.
- For instance, a `Rectangle` struct might have fields like `width` and `height`.

- Encapsulation:
- Structs facilitate encapsulation by allowing the grouping of data and associated methods within a single unit.
- This helps in creating modular and organized code.

Enums (Enumerations):

1. Definition:
- Enums are a data type that allows you to define a type by enumerating its possible variants.
- Each variant can have associated data or be unit-like (without any associated data).

2. Example:
```rust
enum TrafficLight {
Red,
Yellow,
Green,
}
```

3. Use Cases:
- Representing Finite States:
- Enums are well-suited for situations where a type can exist in a finite set of distinct states.
- For example, a `TrafficLight` enum represents the three possible states of a traffic light.

- Modeling Options:
- Enums are commonly used to represent options or choices in a type.
- An `Option` enum, for instance, can be either `Some` with associated data or `None`.

- Error Handling:
- Enums are employed in Rust's error handling using the `Result` type, where `Ok` and `Err` are variants indicating success or failure.
- This helps in handling errors in a structured and explicit manner.

- Pattern Matching:
- Enums are often used with pattern matching (match statements) to provide concise and expressive code for handling different cases.

Summary:

In summary, structs are ideal for organizing related data fields under a single name, encapsulating objects, and providing a structured way to represent data. On the other hand, enums are powerful for representing types with a finite set of distinct states, modeling options and choices, and facilitating explicit error handling. The combination of structs and enums in Rust enables developers to create flexible and robust data structures to address a wide range of programming scenarios.