Book Image

Modern C++ Programming Cookbook - Third Edition

By : Marius Bancila
Book Image

Modern C++ Programming Cookbook - Third Edition

By: Marius Bancila

Overview of this book

The updated third edition of Modern C++ Programming Cookbook addresses the latest features of C++23, such as the stack library, the expected and mdspan types, span buffers, formatting library improvements, and updates to the ranges library. It also gets into more C++20 topics not previously covered, such as sync output streams and source_location. The book is organized in the form of practical recipes covering a wide range of real-world problems. It gets into the details of all the core concepts of modern C++ programming, such as functions and classes, iterators and algorithms, streams and the file system, threading and concurrency, smart pointers and move semantics, and many others. You will cover the performance aspects of programming in depth, and learning to write fast and lean code with the help of best practices. You will explore useful patterns and the implementation of many idioms, including pimpl, named parameter, attorney-client, and the factory pattern. A chapter dedicated to unit testing introduces you to three of the most widely used libraries for C++: Boost.Test, Google Test, and Catch2. By the end of this modern C++ programming book, you will be able to effectively leverage the features and techniques of C++11/14/17/20/23 programming to enhance the performance, scalability, and efficiency of your applications.
Table of Contents (15 chapters)
13
Other Books You May Enjoy
14
Index

Using string_view instead of constant string references

When working with strings, temporary objects are created all the time, even if you might not be really aware of it. Many times, these temporary objects are irrelevant and only serve the purpose of copying data from one place to another (for example, from a function to its caller). This represents a performance issue because they require memory allocation and data copying, which should be avoided. For this purpose, the C++17 standard provides a new string class template called std::basic_string_view that represents a non-owning constant reference to a string (that is, a sequence of characters). In this recipe, you will learn when and how you should use this class.

Getting ready

The string_view class is available in the namespace std in the string_view header.

How to do it...

You should use std::string_view to pass a parameter to a function (or return a value from a function), instead of std::string const &, unless your code...