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

Advancing from abstract ranges to the ranges library

We have used the term range many times in the previous chapter. A range is an abstraction of a sequence of elements, delimited by two iterators (one to the first element of the sequence, and one to the one-past-the-last element). Containers such as std::vector, std::list, and std::map are concrete implementations of the range abstraction. They have ownership of the elements and they are implemented using various data structures, such as arrays, linked-lists, or trees. The standard algorithms are generic. They are container-agnostic. They know nothing about std::vector, std::list, or std::map. They handle range abstractions with the help of iterators. However, this has a shortcoming: we always need to retrieve a beginning and end iterator from a container. Here are some examples:

// sorts a vector
std::vector<int> v{ 1, 5, 3, 2, 4 };
std::sort(v.begin(), v.end());
// counts even numbers in an array
std::array<int, 5&gt...