C++: A Dialog Programming with the C++ Standard Library

Modules vs. Functions

Susan had a question about this new notion of a function, as related to modules:

Susan: So a module has nothing to do with blocks and functions? If a function only "calls" another function, then how do you call a module?

Steve: You can't call a module. In fact, although a few language features apply to modules rather than functions, modules don't really have much significance in C++ other than as places to store related functions.

When we call a function, we usually have to provide it with input (for example, some values to be averaged) and it usually produces output which we use in further processing (for example, the average of the input values). Some functions, though, have only one or the other. For example, some functions ...