Book Image

Modern C++ Programming Cookbook - Second Edition

By : Marius Bancila
5 (1)
Book Image

Modern C++ Programming Cookbook - Second Edition

5 (1)
By: Marius Bancila

Overview of this book

C++ has come a long way to be one of the most widely used general-purpose languages that is fast, efficient, and high-performance at its core. The updated second edition of Modern C++ Programming Cookbook addresses the latest features of C++20, such as modules, concepts, coroutines, and the many additions to the standard library, including ranges and text formatting. The book is organized in the form of practical recipes covering a wide range of problems faced by modern developers. The book also delves into the details of all the core concepts in modern C++ programming, such as functions and classes, iterators and algorithms, streams and the file system, threading and concurrency, smart pointers and move semantics, and many others. It goes into the performance aspects of programming in depth, teaching developers how to write fast and lean code with the help of best practices. Furthermore, the book explores useful patterns and delves into the implementation of many idioms, including pimpl, named parameter, and attorney-client, teaching techniques such as avoiding repetition with the factory pattern. There is also a chapter dedicated to unit testing, where you are introduced to three of the most widely used libraries for C++: Boost.Test, Google Test, and Catch2. By the end of the book, you will be able to effectively leverage the features and techniques of C++11/14/17/20 programming to enhance the performance, scalability, and efficiency of your applications.
Table of Contents (16 chapters)
13
Bibliography
14
Other Books You May Enjoy
15
Index

Using fold expressions to simplify variadic function templates

In this chapter, we are discussing folding several times; this is an operation that applies a binary function to a range of values to produce a single value. We have seen this when we discussed variadic function templates, and will see it again with higher-order functions. It turns out there is a significant number of cases where the expansion of a parameter pack in variadic function templates is basically a folding operation. To simplify writing such variadic function templates, C++17 introduced fold expressions, which fold an expansion of a parameter pack over a binary operator. In this recipe, we will learn how to use fold expressions to simplify writing variadic function templates.

Getting ready

The examples in this recipe are based on the variadic function template add (), which we wrote in the previous recipe, Writing a function template with a variable number of arguments. That implementation is a left...