The key points to study in order to master OOP programming in Modern C++:

A piece of advice for those looking to master Object-Oriented Programming in Modern C++: You should focus on understanding the following key points, which are well explained in many sources online. Mastering these mentioned points will allow you to dive deep into the world of programming, covering its most essential details. You will be able to create software of various levels and specializations with ease because you will have mastered the right and powerful approach in today's programming world. Especially, mastering it through a language that is very rich in these concepts and offers immense capabilities. Here are the points, and if any experts notice missing ones, please feel free to mention them in the comments.

1. Introduction to OOP in C++:

   • Definition of Object-Oriented Programming.

   • The evolution of OOP in C++.

   • Differences between classical C++ and Modern C++ in OOP.

2. Fundamental OOP Concepts:

   • Classes and Objects.

   • Inheritance and its types (public, private, protected).

   • Encapsulation and Abstraction.

   • Polymorphism and its types (Compile-time vs Run-time).

3. Modern OOP Features in Modern C++:

   • Initializer Lists.

   • Constructors and Destructors (Default, Copy, Move).

   • Move Semantics and Rvalue References.

   • Smart Pointers (unique_ptr, shared_ptr, weak_ptr) and Object Memory Management.

   • Delegating and Inheriting Constructors.

   • Lambda Functions and their use in OOP.

4. OOP-based Design with C++20:

   • Using Concepts in Object-Oriented Design.

   • Constexpr and its effect on design.

   • Coroutines and their role in asynchronous objects.

5. Design Patterns in C++:

   • Singleton Pattern.

   • Factory Pattern.

   • Observer Pattern.

   • Strategy Pattern.

   • Command Pattern.

   • Template Method.

6. Templates and Modern Polymorphism:

   • Function and Class Templates.

   • Variadic Templates.

   • Template Specialization and Partial Specialization.

   • CRTP (Curiously Recurring Template Pattern).

7. Exception Handling in OOP:

   • Exception Handling.

   • RAII (Resource Acquisition Is Initialization).

   • noexcept and its use in OOP.

8. Integration with Third-Party Libraries:

   • Using Boost libraries in OOP.

   • Utilizing Qt in OOP to simplify C++.

9. Best Practices in OOP with C++:

   • SOLID Principles.

   • DRY (Don't Repeat Yourself).

   • KISS (Keep It Simple, Stupid).

   • Law of Demeter.

10. Testing Object-Oriented Code:

    • Unit Testing with Google Test and Catch2.

    • Mocking and Test-driven development.

11. Static vs Dynamic Variables:

    • Static vs Dynamic Objects.

    • Stack vs Heap memory.

12. Challenges and Common Pitfalls in OOP:

    • Problems with Multiple Inheritance.

    • The Diamond Problem and solving it using Virtual Inheritance.

13. High-Performance Object-Oriented Programming:

    • Performance optimization with Inlining.

    • Avoiding unnecessary repetitions.

    • Efficient memory management.

14. Multithreading in OOP:

    • Thread Safety.

    • Thread-safe shared objects.

    • Mutex and Locks in Object-Oriented Programming.

It is important to note that the available documentation on these topics is rich and diverse, but try to read what you find easiest to understand and in the style that helps you grasp these points more quickly. Don’t forget that the key to mastering all these topics is practice, practice, and more practice. Wishing all followers the best of luck.