Book Image

Template Metaprogramming with C++

By : Marius Bancila
5 (1)
Book Image

Template Metaprogramming with C++

5 (1)
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)
1
Part 1: Core Template Concepts
5
Part 2: Advanced Template Features
9
Part 3: Applied Templates
Appendix: Closing Notes

Exploring SFINAE and its purpose

When we write templates, we sometimes need to restrict the template arguments. For instance, we have a function template that should work for any numeric type, therefore integral and floating-point, but should not work with anything else. Or we may have a class template that should only accept trivial types for an argument.

There are also cases when we may have overloaded function templates that should each work with some types only. For instance, one overload should work for integral types and the other for floating-point types only. There are different ways to achieve this goal and we will explore them in this chapter and the next.

Type traits, however, are involved in one way or another in all of them. The first one that will be discussed in this chapter is a feature called SFINAE. Another approach, superior to SFINAE, is represented by concepts, which will be discussed in the next chapter.

SFINAE stands for Substitution Failure Is Not...