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

Virtual Constructors and Factories

In C++, any member function of any class, including its destructor, can be made virtual - any member function except one—the constructor. Without virtual functions, the exact type of object on which the member function is invoked is known at compile time. Therefore, the type of object that is constructed is always known at compile time, at the point of the constructor call. Nonetheless, we often need to construct objects whose type is not known until runtime. This chapter describes several related patterns and idioms that address this design problem in various ways, including the Factory pattern.

The following topics will be covered in this chapter:

  • Why there is no way to make a constructor virtual
  • How to use the Factory pattern to defer the choice of the constructed object type until compile time
  • Using C++ idioms to construct and copy objects polymorphically