Book Image

Modern C++ Programming Cookbook

By : Marius Bancila
Book Image

Modern C++ Programming Cookbook

By: Marius Bancila

Overview of this book

C++ is one of the most widely used programming languages. Fast, efficient, and flexible, it is used to solve many problems. The latest versions of C++ have seen programmers change the way they code, giving up on the old-fashioned C-style programming and adopting modern C++ instead. Beginning with the modern language features, each recipe addresses a specific problem, with a discussion that explains the solution and offers insight into how it works. You will learn major concepts about the core programming language as well as common tasks faced while building a wide variety of software. You will learn about concepts such as concurrency, performance, meta-programming, lambda expressions, regular expressions, testing, and many more in the form of recipes. These recipes will ensure you can make your applications robust and fast. By the end of the book, you will understand the newer aspects of C++11/14/17 and will be able to overcome tasks that are time-consuming or would break your stride while developing.
Table of Contents (19 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

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 that fold an expansion of a parameter pack over a binary operator. In this recipe, we will see 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() that we wrote in the previous recipe, Writing a function template with a variable number of arguments. That implementation is a left-folding operation. For simplicity...