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 functions by concatenation


A lot of tasks are not really worthy of being implemented in completely custom code. Let's, for example, have a look on how a programmer might solve the task of finding out how many unique words a text contains with the programming language Haskell. The first line defines a function unique_words and the second one demonstrates its use with an example string:

Wow, that is short! Without explaining Haskell syntax too much, let's see what the code does. It defines the function called unique_words, which applies a series of functions to its input. It first maps all the characters from the input to lowercase with map toLower. This way, words like FOO and foo can be regarded as the same word. Then, the words function splits a sentence into individual words, as from "foo bar baz" to ["foo", "bar", "baz"]. Next step is sorting the new list of words. This way, a word sequence such as ["a", "b", "a"] becomes ["a", "a", "b"]. Now, the group function takes over. It...