Book Image

Hands-On Design Patterns with C++

By : Fedor G. Pikus
Book Image

Hands-On Design Patterns with C++

By: Fedor G. Pikus

Overview of this book

C++ is a general-purpose programming language designed with the goals of efficiency, performance, and flexibility in mind. 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. The focus of this book is on the design patterns that naturally lend themselves to the needs of a C++ programmer, and on the patterns that uniquely benefit from the features of C++, in particular, the generic programming. Armed with the knowledge of these patterns, you will spend less time searching for a solution to a common problem and be familiar with the solutions developed from experience, as well as their advantages and drawbacks. The other use of design patterns is as a concise and an efficient way to communicate. A pattern is a familiar and instantly recognizable solution to specific problem; through its use, sometimes with a single line of code, we can convey a considerable amount of information. The code conveys: "This is the problem we are facing, these are additional considerations that are most important in our case; hence, the following well-known solution was chosen." By the end of this book, you will have gained a comprehensive understanding of design patterns to create robust, reusable, and maintainable code.
Table of Contents (21 chapters)

Chapter 6

  • What is type erasure really?

Type erasure is a programming technique where the program, as written, does not show an explicit dependence on some of the types it uses.

  • How is type erasure implemented in C++?

Part of the implementation always involves a polymorphic object and a virtual function call or a dynamic cast. Usually, this is combined with generic programming to construct such polymorphic objects.

  • What is the difference between hiding a type behind auto and erasing it?

A program may be written in a way that avoids explicit mention of most types. The types are deduced by template functions and declared as auto or as template-deduced typedef types. However, the actual types of the objects that are hidden by auto still depend on all types the object operates on (such as the deleter type for a pointer). The erased type is not captured by the object type at...