Book Image

Template Metaprogramming with C++

By : Marius Bancila
Book Image

Template Metaprogramming with C++

By: Marius Bancila

Overview of this book

Learn how the metaprogramming technique enables you to create data structures and functions that allow computation to happen at compile time. With this book, you'll realize how templates help you avoid writing duplicate code and are key to creating generic libraries, such as the standard library or Boost, that can be used in a multitude of programs. The introductory chapters of this book will give you insights into the fundamentals of templates and metaprogramming. You'll then move on to practice writing complex templates and exploring advanced concepts such as template recursion, template argument deduction, forwarding references, type traits, and conditional compilation. Along the way, you'll learn how to write variadic templates and how to provide requirements to the template arguments with C++20 constraints and concepts. Finally, you'll apply your knowledge of C++ metaprogramming templates to implement various metaprogramming patterns and techniques. By the end of this book, you'll have learned how to write effective templates and implement metaprogramming in your everyday programming journey.
Table of Contents (16 chapters)
Part 1: Core Template Concepts
Part 2: Advanced Template Features
Part 3: Applied Templates
Appendix: Closing Notes

Dynamic versus static polymorphism

When you learn about object-oriented programming, you learn about its fundamental principles, which are abstraction, encapsulation, inheritance, and polymorphism. C++ is a multi-paradigm programming language that supports object-oriented programming too. Although a broader discussion on the principles of object-oriented programming is beyond the scope of this chapter and this book, it is worth discussing at least some aspects related to polymorphism.

So, what is polymorphism? The term is derived from the Greek words for “many forms”. In programming, it’s the ability of objects of different types to be treated as if they were of the same type. The C++ standard actually defines a polymorphic class as follows (see C++20 standard, paragraph 11.7.2, Virtual functions):

A class that declares or inherits a virtual function is called a polymorphic class.

It also defines polymorphic objects based on this definition, as follows...