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 virtual function calls in constant expressions

As a multi-paradigm programming language, C++ includes support for object-oriented programming. Polymorphism, one of the core principles of object-oriented programming, has two forms in C++: compile-time polymorphism, with function and operator overloading, and runtime-polymorphism, with virtual functions. Virtual functions allow a derived class to override the implementation (of a function) in the base class. In C++20, however, virtual functions are allowed in constant expressions, meaning they can be invoked at compile time. In this recipe, you will learn how that works.

Getting ready

In this recipe, we will use the following structure to represent the dimension of a document and, respectively, an envelope, in the ensuing examples:

struct dimension
{
   double width;
   double height;
};

How to do it…

You can move runtime polymorphism to the compile time by doing the following:

  • Declare the...