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

Catching readable exceptions from std::iostream errors


In none of the recipes in this chapter, we used exceptions to catch errors. While this is certainly possible, working on stream objects without exceptions is already very convenient. If we try to parse in 10 values, but this fails somewhere in the middle, the whole stream object sets itself into a fail state and stops further parsing. This way, we do not run into the danger of parsing variables from the wrong offset in the stream. We can just do the parsing in a conditional, such as if (cin >> foo >> bar >> ...). If this fails, we handle it. It does not appear very advantageous to embrace parsing in a try { ... } catch ... block.

In fact, the C++ I/O stream library already existed before there were exceptions in C++. Exception support was added later, which might be an explanation why they are not a first-class supported feature in the stream library.

In order to use exceptions in the stream library, we must configure...