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 explored the concept of type traits, which are small classes that define meta-information about types or transformation operations for types. We started by looking at how type traits can be implemented and how they help us. Next, we learned about SFINAE, which stands for Substitution Failure Is Not An Error. This is a technique that enables us to provide constraints for template parameters.

We then saw how this purpose can be achieved better with enable_if and constexpr if, in C++17. In the second part of the chapter, we looked at the type traits available in the standard library and demonstrated how to use some of them. We ended the chapter with a couple of real-world examples where we used multiple type traits to solve a particular problem.

In the next chapter, we continue the topic of constraining the template parameters by learning about the C++20 concepts and constraints.