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

Handling friendship with the attorney-client idiom

Granting functions and classes access to the non-public parts of a class with a friend declaration has been usually seen as a sign of bad design, as friendship breaks encapsulation and ties classes and functions. Friends, whether they are classes or functions, get access to all the private parts of a class, although they may only need to access parts of it.

The attorney-client idiom provides a simple mechanism to restrict friends access to only designated private parts of a class.

Getting ready

To demonstrate how to implement this idiom, we will consider the following classes: Client, which has some private member data and functions (the public interface is not important here), and Friend, which is supposed to access only parts of the private details, for instance, data1 and action1(), but has access to everything:

class Client
{
  int data_1;
  int data_2;
  void action1() {}
  void action2() {}
  friend class...