C++ For Dummies, 7th Edition

Chapter 10

The C++ Preprocessor

In This Chapter

Including source files

Defining constants and macros

Enumerating alternatives to constants

Inserting compile-time checks

Simplifying declarations via typedef

You only thought that all you had to learn was C++. It turns out that C++ includes a preprocessor that works on your source files before the “real C++ compiler” ever gets to see it. Unfortunately, the syntax of the preprocessor is completely different than that of C++ itself.

Before you despair, however, let me hasten to add that the preprocessor is very basic and the C++ ’11 standard has added a number of features that make the preprocessor almost unnecessary. Nevertheless, if the conversation turns to C++ at your next Coffee Club meeting, you’ll be expected to understand the preprocessor.

What Is a Preprocessor?

Up until now, you may have thought of the C++ compiler as munching on your source code and spitting out an executable program in one step, but that isn’t quite true. ...