Book Image

Modern C++ Programming Cookbook

By : Marius Bancila
Book Image

Modern C++ Programming Cookbook

By: Marius Bancila

Overview of this book

C++ is one of the most widely used programming languages. Fast, efficient, and flexible, it is used to solve many problems. The latest versions of C++ have seen programmers change the way they code, giving up on the old-fashioned C-style programming and adopting modern C++ instead. Beginning with the modern language features, each recipe addresses a specific problem, with a discussion that explains the solution and offers insight into how it works. You will learn major concepts about the core programming language as well as common tasks faced while building a wide variety of software. You will learn about concepts such as concurrency, performance, meta-programming, lambda expressions, regular expressions, testing, and many more in the form of recipes. These recipes will ensure you can make your applications robust and fast. By the end of the book, you will understand the newer aspects of C++11/14/17 and will be able to overcome tasks that are time-consuming or would break your stride while developing.
Table of Contents (19 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

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 indeed. 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 as constant:

 

  • 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...