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

Composing useful algorithms from standard algorithms - gather


A very nice example for the composability of STL algorithms is gather. Sean Parent, principal scientist at Adobe Systems at the time, popularized this algorithm because it is both useful and short. The way it is implemented, it is the ideal poster child for the idea of STL algorithm composition.

The gather algorithm operates on ranges of arbitrary item types. It modifies the order of the items in such a way that specific items are gathered around a specific position, chosen by the caller.

How to do it...

In this section, we will implement the gather algorithm and a bonus variation of it. Afterward, we see how it can be put to use:

  1. First, we add all the STL include statements. Then, we declare that we use the std namespace:
      #include <iostream>
      #include <algorithm>
      #include <string>
      #include <functional>      

      using namespace std;
  1. The gather algorithm is a nice example of standard...