The enum_info_base Class

Each type info class for a VHDL enumeration type is derived from enum_info_base. The different enumeration values are represented by integers. The values assigned to the different elements of an enumeration type are assigned as follows:

• If the enumeration type is a new defined type, then the leftmost element is assigned the value 0, the next element is assigned 1, ...
• If the enumeration type is derived from a existing enumeration type via a subtype definition, then the values which are assigned to the various enumeration elements are taken from the corresponding basic enumeration type.

Example: For a enumeration type myenum defined as follows

TYPE myenum is (blue, red, green, yellow);

blue is assigned 0, red is assigned 1, green is assigned 2 and yellow is assigned 3. If a enumeration subtype is derived from myenum

SUBTYPE derived_myenum is red TO green;

then red is assigned 1 and green is assigned 2 for type derived_myenum.