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

Chaining together computations that may or may not produce a value

In the previous recipe, we have seen how to use the std::optional class for storing a value that may or may not exist. Its use cases include optional parameters to functions and return values from functions that may fail to produce a result. When multiple such functions need to be chained together, the code can become cumbersome and verbose. For this reason, the C++23 standard has added several new methods to the std::optional class. They are referred to by the term monadic operations. These methods are transform(), and_then(), and or_else(). In this recipe, we’ll see what they are useful for.

In simple terms, in functional programming, a monad is a container that encapsulates some functionality on top of a value that it wraps. Such an example is std::optional in C++. On the other hand, a monadic operation is a function from a domain D into D itself. For instance, the identity function (a function...