- best practice — enclose in a namespace or a class
- enum can group 2 related constants. Scoped enum is even more descriptive.
- enum also creates a typename for code documentation
- enum const value must be signed integers 😦
- Both enum type and a single static const field can be declared as class members 🙂
- For singular constants, use enum or const static variables (file-scope, and independently instantiated in each compilation unit). Avoid extern.