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Rust provides powerful abstractions for managing memory safely and efficiently. One such abstraction is Rc (Reference Counting), which allows multiple ownership of data. When combined with RefCell, it unlocks the ability to mutate data through shared ownership safely at runtime.

In this challenge, you'll use Rc and RefCell together to explore the concept of Interior Mutability in Rust.

Your Task

Implement the following functions to demonstrate shared ownership and interior mutability:

  1. push:

    • Accept an Rc<RefCell<Vec<T>>> as input.
    • Append an element to the shared vector inside the RefCell.

  2. iterate_and_print_shared_data:

    • Take an Rc<RefCell<Vec<T>>> as input.
    • Iterate through the vector and print each element.

  3. plus_one:

    • Accept an Rc<RefCell<i32> as input.
    • Increment the value inside the RefCell by one.

Requirements

  • Use Rc to share ownership of the vector.
  • Use RefCell to allow interior mutability.
  • Avoid using unsafe code.

Hints

If you're stuck, here are some hints to help you solve the challenge:

<details> <summary>Click here to reveal hints</summary>
  • Use Rc::clone to share ownership of the vector.
  • Use RefCell's .borrow_mut() for mutable access and .borrow() for immutable access.
  • T: Display is needed to format the output with println!.
</details>
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use std::cell::RefCell;
use std::rc::Rc;


pub fn push<T>(data: Rc<RefCell<Vec<T>>>, element: T) {
    // 1. Finish the function
}


pub fn iterate_and_print_shared_data<T>(data: Rc<RefCell<Vec<T>>>) {
    // 2. Borrow the data and print each item
}


pub fn plus_one(data: Rc<RefCell<i32>>) {
    // 3. Finish the function
}


// Example usage
pub fn main() {
    let shared_data = Rc::new(RefCell::new(vec![1, 2, 3]));


    // Updating shared data
    push(Rc::clone(&shared_data), 4);
    push(Rc::clone(&shared_data), 5);


    // Iterating and printing shared data
    println!("Shared Data:");
    iterate_and_print_shared_data(Rc::clone(&shared_data));


    let my_num = Rc::new(RefCell::new(5));
    plus_one(Rc::clone(&my_num));
    assert_eq!(*my_num.borrow(), 6, "Value was not incremented correctly.");
}