Registering Soft UDPs with an enum as the valid_type

[rbroich]

I have a user defined property defined as follows in an RDL file:

enum E_FIELD_TYPE {
    FT_UNSIGNED {desc = "Unsigned integer number from 0 to 2^bits - 1";};
    FT_SIGNED {desc = "Signed number from -2^(bits-1) to 2^(bits-1) - 1";};
    FT_BOOL {desc = "Boolean value: true or false";};
};
property field_type {
    component = field;
    type = E_FIELD_TYPE;
};

A custom generator then makes use of this and everything works fine. After reading about Soft UDPs and the validation and unassigned default benefits they provide, I would like to register this property as a soft definition. Here is what I have tried so far:

class FieldTypeDefinition(UDPDefinition):
    name = "field_type"
    valid_components = {Field}
    valid_type = rdltypes.user_enum.UserEnum

This results in:

error: The property definition for the feature extension 'field_type' uses a different 'type' definition from what this tool expects

Is there any way to do this? I have thought about defining the enum in a separate file and compiling it first (rdlc.compile_file) before registering the UDP (rdlc.register_udp), but then I don't have a way to reference it from inside the FieldTypeDefinition class. I suppose creating the enum inside the class could work, but the existing_udp.valid_type != udp.valid_type rulebook entry would still complain then.

Do you have any other suggestions?