Book Image

C++17 STL Cookbook

By : Jacek Galowicz
Book Image

C++17 STL Cookbook

By: Jacek Galowicz

Overview of this book

C++ has come a long way and is in use in every area of the industry. Fast, efficient, and flexible, it is used to solve many problems. The upcoming version of C++ will see programmers change the way they code. If you want to grasp the practical usefulness of the C++17 STL in order to write smarter, fully portable code, then this book is for you. Beginning with new language features, this book will help you understand the language’s mechanics and library features, and offers insight into how they work. Unlike other books, ours takes an implementation-specific, problem-solution approach that will help you quickly overcome hurdles. You will learn the core STL concepts, such as containers, algorithms, utility classes, lambda expressions, iterators, and more, while working on practical real-world recipes. These recipes will help you get the most from the STL and show you how to program in a better way. By the end of the book, you will be up to date with the latest C++17 features and save time and effort while solving tasks elegantly using the STL.
Table of Contents (18 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Creating complex predicates with logical conjunction


When filtering data with generic code, we end up defining predicates, which tell what data we want, and what data we do not want. Sometimes predicates are the combinations of different predicates.

When filtering strings, for example, we could implement a predicate that returns true if its input string begins with "foo". Another predicate could return true if its input string ends with "bar".

Instead of writing custom predicates all the time, we can reuse predicates by combining them. If we want to filter strings that begin with "foo" and end with "bar", we can just pick our existing predicates and combine them with a logical and. In this section, we play with lambda expressions in order to find a comfortable way to do this.

How to do it...

We will implement very simple string filter predicates, and then we will combine them with a little helper function that does the combination for us in a generic way.

  1. As always, we'll include some headers...