C++ How to Program, Ninth Edition

E. Preprocessor

Hold thou the good; define it well.

—Alfred, Lord Tennyson

I have found you an argument; but I am not obliged to find you an understanding.

—Samuel Johnson

A good symbol is the best argument, and is a missionary to persuade thousands.

—Ralph Waldo Emerson

Conditions are fundamentally sound.

—Herbert Hoover [December 1929]

Objectives

In this appendix you’ll learn:

• To use #include for developing large programs.

• To use #define to create macros and macros with arguments.

• To understand conditional compilation.

• To display error messages during conditional compilation.

• To use assertions to test if the values of expressions are correct.

Outline

E.1 Introduction

E.2 #include Preprocessing Directive

E.3 #define Preprocessing ...