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

Converting between absolute and relative times with std::chrono


Until C++11, it was quite a hassle to take the wall clock time and just print it, because C++ did not have its own time library. It was always necessary to call functions of the C library, which looks very archaic, considering that such calls could be encapsulated nicely into their own classes.

Since C++11, the STL provides the chrono library, which makes time-related tasks much easier to implement.

In this recipe, we are going to take the local time, print it, and play around by adding different time offsets, which is a really comfortable thing to do with std::chrono.

How to do it...

We are going to save the current time and print it. Additionally, our program will add different offsets to the saved time point and print the resulting time points too:

  1. The typical include lines come first; then, we declare that we use the std namespace by default:
      #include <iostream>
      #include <iomanip>
      #include <chrono...