Swift Valid and Invalid enums with reasons

valid_invalid_enum_and_why.swift

//Define a class Cat
class Cat {
    
}

enum EnumWithRaw : Cat{
    /*  
        INVALID
        [Error]:    Raw Type Cat is not convertible from any literal
        [Reason]:   Raw value of enum have to be of type strings, characters, or any of the integer or floating-point number types.
                    Which is convertible from literal.
                    I explained what is literal in another issue here. http://stackoverflow.com/a/28935922/1239426
    */
}

// OK. Then what is valid. This one?

enum EnumWithRawNoCase : Character{
    /*  
        INVALID
        [Error]:    An Enum with no cases cannot declare a raw value.
        [Reason]:   Have to have at least one case.
    */
}

enum EnumWithValidRaw : Character{
    case NewLine = "\n"
    /*
        VALID
        Finally Valid.
    */    
}

enum EnumWithoutAnyCase {
    /*
        VALID 
        Is is legal to just define an enum without raw value without members. No use though.
    */
}