Book Image

Hands-On Design Patterns with C++ (Second Edition) - Second Edition

By : Fedor G. Pikus
5 (1)
Book Image

Hands-On Design Patterns with C++ (Second Edition) - Second Edition

5 (1)
By: Fedor G. Pikus

Overview of this book

C++ is a general-purpose programming language designed for efficiency, performance, and flexibility. Design patterns are commonly accepted solutions to well-recognized design problems. In essence, they are a library of reusable components, only for software architecture, and not for a concrete implementation. This book helps you focus on the design patterns that naturally adapt to your needs, and on the patterns that uniquely benefit from the features of C++. Armed with the knowledge of these patterns, you’ll spend less time searching for solutions to common problems and tackle challenges with the solutions developed from experience. You’ll also explore that design patterns are a concise and efficient way to communicate, as patterns are a familiar and recognizable solution to a specific problem and can convey a considerable amount of information with a single line of code. By the end of this book, you’ll have a deep understanding of how to use design patterns to write maintainable, robust, and reusable software.
Table of Contents (26 chapters)
1
Part 1: Getting Started with C++ Features and Concepts
5
Part 2: Common C++ Idioms
10
Part 3: C++ Design Patterns
18
Part 4: Advanced C++ Design Patterns

CRTP and policy-based design

Policy-based design is a compile-time variant of the well-known Strategy pattern; we have an entire chapter dedicated to it, Chapter 15, aptly named Policy-Based Design. Here, we’re going to stay focused on the use of CRTP to provide additional functionality to the derived classes. Specifically, we are going to generalize the use of CRTP base classes to extend the interface of the derived class.

So far, we have used one base class to add features to the derived class:

template <typename D> struct plus_base {…};
class D : public plus_base<D> {…};

However, if we want to extend the interface of the derived class in multiple ways, a single base class presents an unnecessary restriction. First of all, if we add several member functions, the base class can get quite large. Second, we may want a more modular approach to the interface design. For example, we can have one base class template that adds factory construction...