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 4, Advanced Template Concepts

Question 1

When is name lookup performed?


Name lookup is performed at the point of template instantiation for dependent names (those that depend on the type or value of a template parameter) and at the point of template definition for non-dependent names (those that don’t depend on template parameters).

Question 2

What are deduction guides?


Deduction guides are a mechanism that tells the compiler how to perform class template argument deduction. Deduction guides are fictional function templates representing constructor signatures of a fictional class type. If overload resolution fails on the constructed set of fictional function templates, then the program is ill-formed and an error is generated. Otherwise, the return type of the selected function template specialization becomes the deduced class template specialization.

Question 3

What are forwarding references?


A forward reference...