Clean way to not get object back from instantiation attempt gone bad

[John Machin]

Simon Forman wrote:

> The entire post was meant as a pedantic exercise illustrating what not
> to do (and how easy it is to figure that out with an interactive
> session,) and sketching how to raise and check for an error instead.
>

Lessons usually start with the teacher asserting authority and stating
the objective of the lesson, especially if the main content is a list
of things the students should *not* do. Otherwise, casual observers can
only apply duck-typing :-)

> Peace,

et pax vobiscum ...