Mastering C++ Class Constraints: Enforcing Non-Copyability and Non-Movability with the Rule of Five

In Sandor Dargo's blog article, the author discusses various strategies to enforce that a class in C++ is either non-copyable or non-movable, highlighting the importance of using such constraints for different class types, such as resource classes and singleton classes. Dargo introduces the concept of special member functions (SMFs) and emphasizes the relevance of the "Rule of Five" in C++. The article outlines a few methodologies to implement these constraints, including deleting unnecessary SMFs and retrieving documentation on intentions via C++26 features. Additionally, the article proposes using type traits to ensure certain class characteristics and suggests utilizing inheritance to streamline the process. The article concludes by offering practical coding examples and summarizing the discussed approaches.

Key Points:

• Importance of non-copyability and non-movability for specific class types (resource and singleton classes).
• Special Member Functions (SMFs) must be correctly implemented to control class behavior.
• The "Rule of Five" is a proposed guideline for managing SMFs in C++.
• Documentation of intentions can now be done with reasons for deleting SMFs in C++26.
• Using static assertions helps ensure that classes maintain their desired properties.
• Inheritance can simplify the creation of non-copyable or non-movable classes.
• Considerations regarding destructors when using inheritance with base classes.
• The article emphasizes clarity and readability in code for defining class traits.
  Link to Article