C++ All-in-One For Dummies, 4th Edition

Chapter 5

Streaming Your Own Classes

IN THIS CHAPTER

Streaming a class to a text file

Getting the most out of manipulators

Writing your own manipulators

The C++ stream classes can read and write all sorts of goodies, such as integers, characters, strings, floating-point numbers, and Boolean variables. But sooner or later, being able to stream one of your own classes (like the following) would be nice:

MyClass x;cout << x << endl;

C++ has a good reason not to have done this already: The compiler and library can’t predict on their own how you want to stream your class using cout. (The example in the “Writing and reading structured data” section of Chapter 3 of this minibook shows one technique for accomplishing this task by overriding the << operator.) Here are some examples:

• The name of the class followed by the values of the public properties.
• The private properties.
• Derived values or some other information related to the class.

Therefore, you should make the class streamable. This chapter shows you how to do it. But keep in mind that you have (at least) two separate reasons why you may want to make a class streamable:

• To provide a format for writing the object to a text ...