To get the most out of this book, you need to have a basic knowledge of C++. It's preferable if you have already been facing problems related to performance and are now looking for new tools and practices to have ready the next time you need to work with performance and C++.

There are a lot of code examples in this book. Some are taken from the real world, but most of them are artificial or vastly simplified examples to prove a concept rather than providing you with production-ready code. We have put all the code examples in source files divided by chapter so that it is fairly easy to find the examples you want to experiment with. If you open up the source code files, you will note that we have replaced most of the main() functions from the examples with test cases written with Google Test framework. We hope that this will help you rather than confuse you. It allowed us to write helpful descriptions for each example, and it also makes it easier to run all the examples from one chapter at once.

In order to compile and run the examples, you will need the following:

• A computer
• An operation system (we have verified the examples on Windows and macOS)
• A compiler (we have been using Clang, GCC, and Microsoft Visual C++)
• CMake

The CMake script provided with the example code will download and install further dependencies such as Boost, OpenCL, and Google Test.

During the writing of this book, it has been of great help for us to use Compiler Explorer, which is available at https://godbolt.org/. Compiler Explorer is an online compiler service that lets you try various compilers and versions. Try it out if you haven't already!

You can download the example code files for this book from your account at www.packtpub.com. If you purchased this book elsewhere, you can visit www.packtpub.com/support and register to have the files emailed directly to you.

You can download the code files by following these steps:

1. Log in or register at www.packtpub.com.
2. Select the SUPPORT tab.
3. Click on Code Downloads & Errata.
4. Enter the name of the book in the Search box and follow the onscreen instructions.

Once the file is downloaded, please make sure that you unzip or extract the folder using the latest version of:

• WinRAR/7-Zip for Windows
• Zipeg/iZip/UnRarX for Mac
• 7-Zip/PeaZip for Linux

The code bundle for the book is also hosted on GitHub at https://github.com/PacktPublishing/Cpp-High-Performance. We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, folder names, filenames, file extensions, dummy URLs, and user input. Here is an example: "The keyword constexpr was introduced in C++11."

A block of code is set as follows:

#include <iostream>

auto main() -> int {
  std::cout << "High Performance C++\n";
}

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

#include <iostream>

auto main() -> int {
  std::cout << "High Performance C++\n";
}

Any command-line input or output is written as follows:

$ clang++ -std=c++17 high_performance.cpp
$ ./a.out
$ High Performance C++

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "Select System info from the Administration panel."