Enum inheritance Support

[lequytra]

Is your feature request related to a problem? Please describe. I have the following code structure:

class EnumBase(Enum):
    pass

class VanillaEnum(EnumBase):
    # some enum values

class ExtendedEnum(EnumBase):
    # some enum values

class Config:
    enum_options: EnumBase

I want Enum inheritance to be supported, such that the enum_options to accept both VanillaEnum and ExtendedEnum. Currently, OmegaConf is throwing errors in the validate_and_convert_to_enum method, that the enums are not valid since it doesn't belong to EnumBase.

Describe the solution you'd like I want Enum Inheritance to be supported so enum_options of type EnumBase can accept child enum classes. Can we: in the validate_and_convert_to_enum method, get the subclasses of enum_type using enum_type.__subclasses__() and try to return subclass[value] when enum_type[value] failed?

Describe alternatives you've considered A clear and concise description of any alternative solutions or features you've considered.

Additional context Add any other context or screenshots about the feature request here.

[odelalleau]

My 2 cents:

• Seems doable and potentially useful
• As discussed elsewhere with @lequytra, there is a workaround which is to generate EnumBase dynamically based on the values found in VanillaEnum and ExtendedEnum. However this makes comparisons more cumbersome and error-prone since for instance cfg.enum_options == VanillaEnum.xyz always evaluates to False (so one would need to compare names or values).
• Couple of things to pay attention to if implemented: (a) make sure that both enum_options=VanillaEnum.xyz and enum_options=xyz are supported (with the latter requiring a check for potentially ambiguous names), and (b) make sure that serialization works as expected