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

Understanding template specialization

A template specialization is the definition created from a template instantiation. The template that is being specialized is called the primary template. You can provide an explicit specialized definition for a given set of template arguments, therefore overwriting the implicit code the compiler would generate instead. This is the technique that powers features such as type traits and conditional compilation, which are metaprogramming concepts we will explore in Chapter 5, Type Traits and Conditional Compilation.

There are two forms of template specialization: explicit (full) specialization and partial specialization. We will look in detail at these two in the following sections.

Explicit specialization

Explicit specialization (also called full specialization) occurs when you provide a definition for a template instantiation with the full set of template arguments. The following can be fully specialized:

  • Function templates
  • ...