In Rust, methods and associated functions are both defined using impl blocks. While they are similar in some ways, they serve different purposes:

1. Associated Functions:

   • Defined without a self parameter.
   • Typically used as constructors or utility functions.
   • Called using the struct's name, e.g., StructName::function_name().

2. Methods:

   • Defined with a self parameter (&self, &mut self, or self).
   • Operate on an instance of the struct.
   • Called on a struct instance using the dot syntax, e.g., instance.method_name().

In the previous challenge, the Logger::log_message was an associated function because it didn't take self as a parameter. In this challenge, you will learn how to create methods that operate on struct instances.

Define a struct Counter that represents a simple counter. Implement methods on this struct to increment, decrement, and get the current count. This will help you understand how to define and use methods that operate on a struct instance.

1. Define a struct Counter with a single field count of type i32.

2. Define a new associated function that acts as a constructor and initializes the count field to 0.

3. Implement the following methods for Counter:

   • increment: Increments the counter by 1.
   • decrement: Decrements the counter by 1.
   • get_count: Returns the current count.

4. Ensure these methods use the correct self parameter type (&self or &mut self) based on their behavior.

5. Make the count field private and provide a public constructor Counter::new that initializes the count to 0.

let mut counter = Counter::new();
counter.increment();
counter.increment();
assert_eq!(counter.get_count(), 2);
 
counter.decrement();
assert_eq!(counter.get_count(), 1);

If you're stuck, you can check out these hints: