Professional C++, 5th Edition

11Odds and Ends

WHAT'S IN THIS CHAPTER?

• What modules are and how to author and consume them
• Details of header files
• The different uses of the static keyword
• C-style variable-length argument lists and preprocessor macros

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This chapter discusses a couple of features of the C++ language that don't readily fit in any other chapter. The chapter starts with a detailed discussion on how modules allow you to write reusable components and contrasts this against the old-style header files. It also includes a discussion of the different uses of the static and extern keywords. The final part of the chapter discusses a few C-style utilities: variable-length argument lists and preprocessor macros.

MODULES

Modules are introduced in Chapter 1, “A Crash Course in C++ and the Standard Library,” and you have already authored and consumed your own simple modules in previous chapters. However, there are quite a few more things to say about modules. Before the introduction of modules in C++20, header files, discussed later in this chapter, were used to provide the interface to a reusable piece of code. Header files do have a number of problems, though, such as ...