This demonstrates usage of our recommendations for using modules:

• Prefer small modules
• Only use partitions if you really must
• Avoid using internal partitions

The intention is to show some real code for context of discussions about using C++ modules.

My goal is not to sell modules. If you prefer not using modules: Use header files. There are good reasons to continue using them.

For me, C++ source code is an asset. The intrinsic value of code using modules is higher (lower entropy), as modules are a higher abstraction, compared to header files, which are basically just the pasting of C++ code into translation units (I've done that for ~36 years now).

Using C++ modules comes at a cost though. Understanding modules requires a certain level of understanding, which isn't needed when using the simple model and tradition of header files.