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

Forwarding references

One of the most important features that were added to the language in C++11 is move semantics, which helps improve performance by avoiding making unnecessary copies. Move semantics are supported by another C++11 feature called rvalue references. Before discussing these, it is worth mentioning that, in C++, we have two kinds of values:

  • lvalues are values that refer to a memory location and, therefore, we can take their address with the & operator. lvalues can appear both on the left and right sides of an assignment expression.
  • rvalues are values that are not lvalues. They are defined by exclusion. rvalues do not refer to a memory location and you can’t take their address with the & operator. rvalues are literals and temporary objects and can only appear on the right side of an assignment expression.


    In C++11, there are a few other value categories, glvalue, prvalue, and xvalue. Discussing them here would not benefit the current topic...