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

Counting all words in a file


Let's say we read a text file and we want to count the number of words in the text. We define that one word is a range of characters between whitespace characters. How do we do it?

We could count the number of spaces, for example, because there must be spaces between words. In the sentence, "John has a funny little dog.", we have five space characters, so we could say there are six words.

What if we have a sentence with whitespace noise, such as " John has \t a\nfunny little dog ."? There are way too many unnecessary spaces in this string, and it's not even only spaces. From the other recipes in this book, we already learned how we can remove such excess whitespace. So, we could first preprocess the string into a normal sentence form and then apply the strategy of counting space characters. Yes, that is doable, but there is a much easier way. Why shouldn't we use what the STL already provides us?

In addition to finding an elegant solution for this problem, we will...