type can only be part of one type enum, second is silently ignored

[matt2e]

Steps:

• define a type enum
• define a second type enum
• define a type that conforms to both
• Expected, it is a case in both.

Use case:

• I can imagine wanting to define a User type and a Group type, and have them both conform to Owner and Beneficiary or something.

//ftl:enum
type EnumType interface{ enumType() }

//ftl:enum
type EnumType2 interface{ enumType2() }

type Example string

func (Example) enumType()  {}
func (Example) enumType2() {}

Current we end up with:

enum EnumType {
    Example String
}

enum EnumType2 {
}

With nothing no errors

[alecthomas]

I don't know if this would be possible to support in other languages. Typically each variant is unique to its containing sum type.

[matt2e]

I'll make it an error for now then and we can revisit later if we want.