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

Defining function templates

Function templates are defined in a similar way to regular functions, except that the function declaration is preceded by the keyword template followed by a list of template parameters between angle brackets. The following is a simple example of a function template:

template <typename T>
T add(T const a, T const b)
   return a + b;

This function has two parameters, called a and b, both of the same T type. This type is listed in the template parameters list, introduced with the keyword typename or class (the former is used in this example and throughout the book). This function does nothing more than add the two arguments and returns the result of this operation, which should have the same T type.

Function templates are only blueprints for creating actual functions and only exist in source code. Unless explicitly called in your source code, the function templates will not be present in the compiled executable. However, when...