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)

Access vector elements directly and safely

The vector is one of the most widely used containers in the STL, and for good reason. It's just as convenient as an array but far more powerful and flexible. It's common practice to use the [] operator to access elements in a vector like this:

vector v{ 19, 71, 47, 192, 4004 };
auto & i = v[2];

The vector class also provides a member function for the same purpose:

auto & i = v.at(2);

The result is the same but there is an important difference. The at() function does bounds checking and the [] operator does not. This is intentional, as it allows the [] operator to maintain compatibility with the original C-array. Let's examine this in a bit more detail.

How to do it…

There are two ways to access an element with an index in a vector. The at() member function does bounds checking, and the [] operator does not.

  • Here's a simple main() function that initializes a vector and accesses an...