One easily overlooked problem with the 0-1-many pattern is that Strings
are Collections. So if you have a String, does it mean one string or
many characters?
VisualWorks has solved this problem in the dependency mechanism by
implementing #asDependentsCollection, #asDependentsDo:,
#asDependentsWith: and #asDependentsWithout: (if I remember correctly;
it's been quite some time since I looked at this).
These work with nil (for no element), instances of DependentsCollection
(for many) and anything else (for one).

I would like to see something like this but abstracted from the concrete
problem (dependency). The 'elements' naming convention would suit me
fine.

Hans-Martin