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


This chapter was dedicated to learning various metaprogramming techniques. We started by understanding the differences between dynamic and static polymorphism and then looked at the curiously recurring template pattern for implementing the latter.

Mixins was another pattern that has a similar purpose as CRTP—adding functionality to classes, but unlike CRTP, without modifying them. The third technique we learned about was type erasure, which allows similar types that are unrelated to be treated generically. In the second part, we learned about tag dispatching – which allow us to select between overloads at compile time, and expression templates – which enable lazy evaluation of a computation at compile-time to avoid inefficient operations that occur at runtime. Lastly, we explored typelists and learned how they are used and how we can implement operations with them.

In the next chapter, we will look at the core pillars of the standard template library...