Module 14: C++ Smart Pointers

• First read this page then start the module with the GitHub classroom link below.
• Github Classroom Link: https://classroom.github.com/a/W_2ovphV

Exercise 1: Basic Usage of unique_ptr

Understand the basic mechanics of unique_ptr and how it manages the lifecycle of a heap-allocated object.

1. In the exercise1 folder of your GitHub repository edit the file main.cpp and create a unique_ptr to manage a dynamically allocated object of a simple class Box. The Box class has one integer member variable and a constructor that sets it.
2. Implement the printBoxValue a function that takes a unique_ptr<Box> by value and prints the value of the Box’s member variable.
3. Demonstrate what happens when you try to copy the unique_ptr.
4. In the README.md file, explain why it is not allowed.

Exercise 2: Transfer of Ownership with unique_ptr

Learn how to transfer ownership of managed objects with unique_ptr.

1. In the exercise2 folder of your GitHub repository edit the file main.cpp and create a unique_ptr managing a Box object.
2. Implement the createBoxWithValue function that returns a unique_ptr.
3. Implement the transferOwnership function to transfer ownership of the Box object from one unique_ptr to another.
4. In the README.md file, explain how the transfer of ownership works.

Exercise 3: Introduction to shared_ptr

Familiarize with the basics of shared_ptr and reference counting.

1. Create several shared_ptr<Box> instances that all manage the same Box object.
2. Print the reference count of these shared pointers.

    cout << "Reference count: " << sharedSmartPointer.use_count() << endl;
   

3. Demonstrate how the reference count changes as shared_ptr instances are created and destroyed.
4. In the README.md file, explain the different ways to create and destroy a shared_ptr.

Exercise 4: Sharing and Releasing with shared_ptr

Learn how shared_ptr allows multiple owners and how to release ownership correctly.

1. Create a shared_ptr<Box> and another one that shares ownership with the first one.
2. Implement a function that takes a shared_ptr<Box> by value and another one by reference.
3. Demonstrate how passing by value and by reference to functions affects the reference count.
4. In the README.md file, explain why passing by value and by reference to functions affects the reference count differently.
5. Use .reset() to release ownership and observe how the object is only destroyed when the last shared_ptr is gone.