Scalar

The Scalar base class disallows non-scalar instantiation.

This constraint simplifies class design and avoids the need for
polymorphic arrays (matlab.mixin.Heterogeneous). Cell arrays or structs
may be used to aggregate Scalar objects.

Class Scalar disables construction of object arrays by "(...)" indexing,
by concatenation (cat, vertcat, horzcat), or with the "empty" function.
Scalar-derived classes can only be instantiated as scalars (length-1
objects). Application of array operations to Scalar-derived objects
result in runtime errors.