Why shouldn't you have polymorphic construction as well as
polymorphic destruction?
And this pattern solves that common place problem.
There are also patterns that fit in to what
are called structural patterns.
Such a pattern includes a pattern
called the facade in which you provide a unified interface.
Another pattern that's very common,
especially in multithreaded current systems called the proxy.
In which you provide a surrogate, maybe to another machine.
So these are structural patterns and they get heavy use, and
they occur as big pieces of code in building some systems.
So again, this is all architectural.
Notice the character of the name, like facade or proxy.
They give you a vivid or factory method.
They give you a vivid way to think about something natural.