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


The C++20 standard introduced some new major features to the language and the standard library. One of these is concepts, which was the topic of this chapter. A concept is a named constraint that can be used to define requirements on template arguments for function templates, class templates, variable templates, and alias templates.

In this chapter, we have explored in detail how we can use constraints and concepts and how they work. We have learned about requires clauses (that determine whether a template participates in overload resolution) and requires expressions (that specify requirements for well-formedness of expressions). We have seen what various syntaxes are for specifying constraints. We also learned about abbreviated function templates that provide a simplified syntax for function templates. At the end of the chapter, we explored the fundamental concepts available in the standard library.

In the next chapter, we will shift our attention toward applying the...