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

SFINAE techniques

The rule that a failure of the template argument substitution is not an error - the SFINAE rule - had to be added to the language simply to make certain narrowly defined template functions possible. But the ingenuity of a C++ programmer knows no bounds, and so SFINAE was repurposed and exploited to manually control the overload set by intentionally causing substitution failures. A huge variety of SFINAE-based techniques were invented over the years until the C++20 concepts made most of them obsolete.

Still, some use of SFINAE remains even in C++20, and then there is the vast body of pre-C++20 code that you may need to read, understand, and maintain.

Let’s start with the applications of SFINAE that are still useful even when concepts are available.

SFINAE in C++20

First of all, even in C++20, there are still “natural” type substitution failures. For example, you may want to write this function:

template <typename T> typename...