We follow a pattern where the OptionsBase struct contains seemingly private members (e.g. _viewMode) with setter functions which emulate designated initialisers.

e.g. to initialise with a viewmode and a deadline.

AutoGetCollection::Options{}.viewMode(auto_get_collection::ViewMode::kViewsPermitted).deadline(someDeadline);

It is confusing because those members are not really private, and are being accessed when using the options. Now that we have designated initialisers we could improve how we initialise options.