Doc: https://docs.python.org/3/library/enum.html
Typing spec: https://typing.python.org/en/latest/spec/enums.html

Base features:

• Differentiating members from non-members
• Create a new type variant for enum literals
• Enum literal expansion
• Write a micro benchmark with large enums
• Enforce implicit @final for Enum classes (with members)
• Support iteration over enums
• Detect enums in all cases (metaclass derives from EnumMeta/EnumType)

Advanced features:

• Infer type for member names and member values.
• Handling of enum.Flag (enum expansion may not be performed for subclasses of enum.Flag)
• Special-case handling of IntEnum, StrEnum, or other custom classes that derive from both Enum and some other class (infer appropriate types for member values)
• Custom __new__ or __init__ methods in enums.
• auto() values
• Support for generate_next_value
• Special-case handling for call to enum class to retrieve member by value (e.g. Color(“red”))
• Function syntax to create Enums