Thinking In C++. Volume 2: Practical Programming

The ideas and understanding in this book have come from many other sources, as well: friends like Andrea Provaglio, Dan Saks, Scott Meyers, Charles Petzold, and Michael Wilk; pioneers of the language like Bjarne Stroustrup, Andrew Koenig, and Rob Murray; members of the C++ Standards Committee like Nathan Myers (who was particularly helpful and generous with his insights), Herb Sutter, PJ Plauger, Pete Becker, Kevlin Henney, David Abrahams, Tom Plum, Reg Charney, Tom Penello, Sam Druker, and Uwe Steinmueller, John Spicer, Steve Adamczyk, and Daveed Vandevoorde; people who have spoken in the C++ track at the Software Development Conference (which Bruce created and developed, and Chuck spoke in); and often students in seminars, who ask the questions we need to hear to make the material clearer^.

The book design, cover design, and cover photo were created by Bruce’s friend Daniel Will-Harris, noted author and designer, who used to play with rub-on letters in junior high school while he awaited the invention of computers and desktop publishing. However, we produced the camera-ready pages ourselves, so the typesetting errors are ours. Microsoft^® Word XP was used to write the book and to create camera-ready pages. The body typeface is Georgia and the headlines are in Verdana. The code type face is Andale Mono^.

We also wish to thank the generous professionals at the Edison Design Group and Dinkumware, Ltd., for giving us complimentary copies of their compiler and library (respectively). Without their assistance some of the examples in this book could not have been tested. We also wish to thank Howard Hinnant and the folks at Metrowerks for a copy of their compiler, and Sandy Smith and the folks at SlickEdit for keeping Chuck supplied with a world-class editing environment for so many years. Greg Comeau also provided a copy of his successful EDG-based compiler, Comeau C++.

A special thanks to all our teachers, and all our students (who are our teachers as well).

Evan Cofsky ([email protected]) provided all sorts of assistance on the server as well as development of programs in his now-favorite language, Python. Sharlynn Cobaugh and Paula Steuer were instrumental assistants, preventing Bruce from being washed away in a flood of projects.

Dawn McGee provided much-appreciated inspiration and enthusiasm during this project. The supporting cast of friends includes, but is not limited to: Mark Western, Gen Kiyooka, Kraig Brockschmidt, Zack Urlocker, Andrew Binstock, Neil Rubenking, Steve Sinofsky, JD Hildebrandt, Brian McElhinney, Brinkley Barr, Bill Gates at Midnight Engineering Magazine, Larry Constantine & Lucy Lockwood, Tom Keffer, Greg Perry, Dan Putterman, Christi Westphal, Gene Wang, Dave Mayer, David Intersimone, Claire Sawyers, The Italians (Andrea Provaglio, Laura Fallai, Marco Cantu, Michael Seaver, Huston Franklin, David Wagstaff, Corrado, Ilsa and Christina Giustozzi), Chris & Laura Strand, The Almquists, Brad Jerbic, John Kruth & Marilyn Cvitanic, Holly Payne (yes, the famous novelist!), Mark Mabry, The Robbins Families, The Moelter Families (& the McMillans), The Wilks, Dave Stoner, Laurie Adams, The Cranstons, Larry Fogg, Mike & Karen Sequeira, Gary Entsminger & Allison Brody, Chester Andersen, Joe Lordi, Dave & Brenda Bartlett, The Rentschlers, The Sudeks, Lynn & Todd, and their families. And of course, Mom & Dad, Sandy, James & Natalie, Kim& Jared, Isaac, and Abbi.

Part 1.Building Stable Systems

Software engineers spend about as much time validating code as they do creating it. Quality is or should be the goal of every programmer, and one can go a long way towards that goal by eliminating problems before they rear their ugly heads. In addition, software systems should be robust enough to behave reasonably in the presence of unforeseen environmental problems.

Exception handling was introduced into C++ to support sophisticated error handling without cluttering code with an inordinate amount of error-handling logic. Chapter 1 shows how proper use of exceptions can make for well-behaved software, and also introduces the design principles that underlie exception-safe code. In Chapter 2 we cover unit testing and debugging techniques intended to maximize code quality long before it’s released. The use of assertions to express and enforce program invariants is a sure sign of an experienced software engineer. We also introduce a simple framework to help mitigate the tedium of unit testing.

1: Exception handling

Improving error recovery is one of the most powerful ways you can increase the robustness of your code.