Book Image

C++20 STL Cookbook

By : Bill Weinman
Book Image

C++20 STL Cookbook

By: Bill Weinman

Overview of this book

Fast, efficient, and flexible, the C++ programming language has come a long way and is used in every area of the industry to solve many problems. The latest version C++20 will see programmers change the way they code as it brings a whole array of features enabling the quick deployment of applications. This book will get you up and running with using the STL in the best way possible. Beginning with new language features in C++20, this book will help you understand the language's mechanics and library features and offer insights into how they work. Unlike other books, the C++20 STL Cookbook takes an implementation-specific, problem-solution approach that will help you overcome hurdles quickly. You'll learn core STL concepts, such as containers, algorithms, utility classes, lambda expressions, iterators, and more, while working on real-world recipes. This book is a reference guide for using the C++ STL with its latest capabilities and exploring the cutting-edge features in functional programming and lambda expressions. By the end of the book C++20 book, you'll be able to leverage the latest C++ features and save time and effort while solving tasks elegantly using the STL.
Table of Contents (13 chapters)

Safely compare integers of different types

Comparing different types of integers may not always produce the expected results. For example:

int x{ -3 };
unsigned y{ 7 };
if(x < y) puts("true");
else puts("false");

You may expect this code to print true, and that's understandable. -3 is usually less than 7. But it will print false.

The problem is that x is signed and y is unsigned. The standardized behavior is to convert the signed type to unsigned for the comparison. That seems counterintuitive, doesn't it? Indeed, you cannot reliably convert an unsigned value to a signed value of the same size, because a signed integer uses two's complement representation (which uses the most significant bit as a sign). Given the same sized integer, the maximum signed value is half that of an unsigned value. Using this example, if your integers are 32-bits, -3 (signed) becomes FFFF FFFD (hexadecimal), or 4,294,967,293 (unsigned decimal), which is not less...