Part 3. Classic (premodern) C++

In software development, grappling with legacy code is an ongoing challenge, particularly for C++ programming. The classic, or premodern, era of C++ is marked by practices developed before modern language features were established, often lacking the safety, efficiency, and simplicity that contemporary features offer. This section delves into these classic coding problems, offering insights and strategies to improve code quality and robustness within the confines of legacy systems.

A critical area of focus is the design and maintenance of class invariants, foundational principles for creating robust and stable applications. Establishing strong class invariants is paramount to ensuring application stability and predictability, yet maintaining these invariants over time, especially as the code base evolves, presents challenges. This section explores past pitfalls and offers guidance on crafting and sustaining class integrity through deliberate design, helping developers shield against the gradual decay of design quality and the improvement of new code.