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

Chapter 5: Type Traits and Conditional Compilation

Type traits are an important metaprogramming technique that enables us to inspect properties of types or to perform transformations of types at compile-time. Type traits are themselves templates and you can see them as meta-types. Knowing information such as the nature of a type, its supported operations, and its various properties is key for performing conditional compilation of templated code. It is also very useful when writing a library of templates.

In this chapter, you will learn the following:

  • Understanding and defining type traits
  • Understanding SFINAE and its purpose
  • Enabling SFINAE with the enable_if type trait
  • Using constexpr if
  • Exploring the standard type traits
  • Seeing real-world examples of using type traits

By the end of the chapter, you will have a good understanding of what type traits are, how they are useful, and what type traits are available in the C++ standard library.