Singleton --- almost

[Ryan Stewart]

[...]

There are times when singletons are the correct pattern to use, but its so
rare that I tend to consider singletons to be an anti-pattern.

Many thanks to all the contributors for your patient, thoughtful explanations. I
believe I have a much clearer idea of the intent if the Singleton pattern.

Design patterns in general are on my (long) list of things to study. Not
something I've gotten to yet.