Learning the fundamentals of a programming language is one thing; learning how to design and implement effective programs in that language is something else entirely. This is especially true of C++, a language boasting an uncommon range of power and expressiveness. Properly used, C++ can be a joy to work with. An enormous variety of designs can be directly expressed and efficiently implemented. A judiciously chosen and carefully crafted set of classes, functions, and templates can make application programming easy, intuitive, efficient, and nearly error-free. It isn't unduly difficult to write effective C++ programs, if you know how to do it. Used without discipline, however, C++ can lead to code that is incomprehensible, unmaintainable, inextensible, inefficient, and just plain wrong.
The purpose of this book is to show you how to use C++ effectively. I assume you already know C++ as a language and that you have some experience in its use. What I provide here is a guide to using the language so that your software is comprehensible, maintainable, portable, extensible, efficient, and likely to behave as you expect.
The advice I proffer falls into two broad categories: general design strategies, and the nuts and bolts of specific language features. The design discussions concentrate on how to choose between different approaches to accomplishing something in C++. How do you choose between inheritance and templates? Between public and private inheritance? Between private inheritance and composition? Between member and non-member functions? Between pass-by-value and pass-by-reference? It's important to make these decisions correctly at the outset, because a poor choice may not become apparent until much later in the development process, at which point rectifying it is often difficult, time-consuming, and expensive.
Even when you know exactly what you want to do, getting things just right can be tricky. What's the proper return type for assignment operators? When should a destructor be virtual? How should operator new behave when it can't find enough memory? It's crucial to sweat details like these, because failure to do so almost always leads to unexpected, possibly mystifying program behavior. This book will help you avoid that.
This is not a comprehensive reference for C++. Rather, it's a collection of 55 specific suggestions (I call them Items) for how you can improve your programs and designs. Each Item stands more or less on its own, but most also contain references to other Items. One way to read the book, then, is to start with an Item of interest, then follow its references to see where they lead you.
The book isn't an introduction to C++, either. In Chapter 2, for example, I'm eager to tell you all about the proper implementations of constructors, destructors, and assignment operators, but I assume you already know or can go elsewhere to find out what these functions do and how they are declared. A number of C++ books contain information such as that.
The purpose of this book is to highlight those aspects of C++ programming that are often overlooked. Other books describe the different parts of the language. This book tells you how to combine those parts so you end up with effective programs. Other books tell you how to get your programs to compile. This book tells you how to avoid problems that compilers won't tell you about.
At the same time, this book limits itself to standard C++. Only features in the official language standard have been used here. Portability is a key concern in this book, so if you're looking for platform-dependent hacks and kludges, this is not the place to find them.
Another thing you won't find in this book is the C++ Gospel, the One True Path to perfect C++ software. Each of the Items in this book provides guidance on how to develop better designs, how to avoid common problems, or how to achieve greater efficiency, but none of the Items is universally applicable. Software design and implementation is a complex task, one colored by the constraints of the hardware, the operating system, and the application, so the best I can do is provide guidelines for creating better programs.
If you follow all the guidelines all the time, you are unlikely to fall into the most common traps surrounding C++, but guidelines, by their nature, have exceptions. That's why each Item has an explanation. The explanations are the most important part of the book. Only by understanding the rationale behind an Item can you determine whether it applies to the software you are developing and to the unique constraints under which you toil.
The best use of this book is to gain insight into how C++ behaves, why it behaves that way, and how to use its behavior to your advantage. Blind application of the Items in this book is clearly inappropriate, but at the same time, you probably shouldn't violate any of the guidelines without a good reason.