Using User Defined Types

16.7 Using User Defined Types

User-defined types can be used to store N-dimensional arrays of structs, variable length arrays, enumerations, and opaque data ojects of known size.

Variables and attributes may be of a user-defined type.
Multiple variables may use the same type.
A user defined type must be defined before it is used to store data or used in the definition of another user-defined type.
When defined, a user type is assigned a typeid (which may not be the same between different openings of the same file).
The typeid is then used when defining a variable or writing an attribute.
User defined types may be nested (in some ways). For example, you can define a compound type, holding a variable-length array of enumerations.