Imagine that you are about to finish a relatively large program, one that has taken a few weeks or months to write and debug. Just as you are putting the finishing touches on it, you discover that it is either too slow or runs out of memory when you feed it a realistic set of input data. You sigh, and start the task of optimizing it.
But why optimize? If your program doesn't fit in memory, you can just get more memory; if it is too slow, you can get a faster processor.
I have written Optimizing C++ because I believe that this common attitude is incorrect, and that a knowledge of optimization is essential to a professional programmer. One very important reason is that we often have little control over the hardware on which our programs are to be run. In this situation, the simplistic approach of adding more hardware is not feasible.
Optimizing C++ provides working programmers and those who intend to be working programmers with a practical, real-world approach to program optimization. Many of the optimization techniques presented are derived from my reading of academic journals that are, sadly, little known in the programming community. This book also draws on my nearly 30 years of experience as a programmer in diverse fields of application, during which I have become increasingly concerned about the amount of effort spent in reinventing optimization techniques rather than applying those already developed.