There are many principles to keep in mind when writing code. When writing object-oriented code, you should be familiar with the quartet of abstraction, encapsulation, inheritance, and polymorphism. Regardless of whether your writing C++ in a mostly object-oriented programming manner or not, you should keep in mind the principles behind the two acronyms: SOLID and DRY.
SOLID is a set of practices that can help you write cleaner and less bug-prone software. It's an acronym made from the first letters of the five concepts behind it:
- Single responsibility principle
- Open-closed principle
- Liskov substitution principle
- Interface segregation
- Dependency Inversion
We assume you already have the idea of how those principles relate to object-oriented programming, but since C++ is not always object-oriented, let's look at how they apply to different areas.
Some of the examples use dynamic polymorphism, but the same would apply to static polymorphism. If you're writing performance-oriented code (and you probably are if you chose C++), you should know that using dynamic polymorphism can be a bad idea in terms of performance, especially on the hot path. Further on in the book, you'll learn how to write statically polymorphic classes using the Curiously Recurring Template Pattern (CRTP).
