Definition from IAI: A collection of simple or measure values
that define a prescribed set of alternatives from which 'enumeration values'
are selected. This enables inclusion of enumeration values in property sets.
IfcPropertyEnumeration provides a name for the enumeration as well as a
list of (numeric or descriptive) values (that have a measure type assigned).
The entity defines the list of potential enumerators to be exchanged.
The unit is handled by the Unit attribute:
- If the Unit attribute is not given, than the unit is already
implied by the type of IfcMeasureValue or IfcDerivedMeasureValue. The
associated unit can be found at the IfcUnitAssignment globally defined at the
project level (IfcProject.UnitsInContext).
- If the Unit attribute is given, the unit assigned by the unit
attribute overrides the globally assigned unit.
ISSUES: See issue log for changes
made IFC Release 2x.
HISTORY: New Entity in IFC Release
2.0, capabilities enhanced in IFC Release 2x. Entity has been renamed from
IfcEnumeration in IFC Release 2x.