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

Ensuring constant correctness for a program

Although there is no formal definition, constant correctness means objects that are not supposed to be modified (are immutable) remain unmodified. As a developer, you can enforce this by using the const keyword for declaring parameters, variables, and member functions. In this recipe, we will explore the benefits of constant correctness and how to achieve it.

How to do it...

To ensure constant correctness for a program, you should always declare the following as constants:

  • Parameters to functions that are not supposed to be modified within the function:
    struct session {};
    session connect(std::string const & uri,
                    int const timeout = 2000)
    {
      /* do something */
      return session { /* ... */ };
    }
    
  • Class data members that do not change:
    class user_settings
    {
    public:
      int const min_update_interval = 15;
      /* other members */
    };
    
  • Class member functions that do not...