Book Image

Modern C++ Programming Cookbook - Second Edition

By : Marius Bancila
5 (1)
Book Image

Modern C++ Programming Cookbook - Second Edition

5 (1)
By: Marius Bancila

Overview of this book

C++ has come a long way to be one of the most widely used general-purpose languages that is fast, efficient, and high-performance at its core. The updated second edition of Modern C++ Programming Cookbook addresses the latest features of C++20, such as modules, concepts, coroutines, and the many additions to the standard library, including ranges and text formatting. The book is organized in the form of practical recipes covering a wide range of problems faced by modern developers. The book also delves into the details of all the core concepts in 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. It goes into the performance aspects of programming in depth, teaching developers how to write fast and lean code with the help of best practices. Furthermore, the book explores useful patterns and delves into the implementation of many idioms, including pimpl, named parameter, and attorney-client, teaching techniques such as avoiding repetition with the factory pattern. There is also a chapter dedicated to unit testing, where you are introduced to three of the most widely used libraries for C++: Boost.Test, Google Test, and Catch2. By the end of the book, you will be able to effectively leverage the features and techniques of C++11/14/17/20 programming to enhance the performance, scalability, and efficiency of your applications.
Table of Contents (16 chapters)
13
Bibliography
14
Other Books You May Enjoy
15
Index

Creating compile-time constant expressions

The possibility to evaluate expressions at compile time improves runtime execution because there is less code to run and the compiler can perform additional optimizations. Compile-time constants can be not only literals (such as a number or string), but also the result of a function's execution. If all the input values of a function (regardless of whether they are arguments, locals, or globals) are known at compile time, the compiler can execute the function and have the result available at compile time. This is what generalized the constant expressions that were introduced in C++11, which were relaxed in C++14 and further more in C++20. The keyword constexpr (short for constant expression) can be used to declare compile-time constant objects and functions. We have seen this in several examples in the previous chapters. Now, it's time to learn how it actually works.

Getting ready

The way generalized constant...