Singleton in Action?

[Alex]

On Sunday, 3 February 2019 at 09:46:20 UTC, Ron Tarrant wrote:
> On Saturday, 2 February 2019 at 20:30:15 UTC, Neia Neutuladh 
> wrote:
>
>> And consider putting the class in its own source file.
>
> Yes, by all means.
>
> Speaking of which...
>
> Considering the nature of a singleton such the one in the top 
> post, I can't see it being possible to use one as a base class 
> from which to derive other classes... speaking from a 
> theoretical POV.
>
> Thanks, guys, for all the input.

Isn't deriving a singleton even eviler as having one? ;)

https://codeblog.jonskeet.uk/2006/01/19/singleton-inheritance/