Different enums, same value in protobuf

Question

I have protocol buffer definitions like this:

package com.asd;

enum AType {
    A1 = 0;
    A2 = 1;
    Unknown = 2;
}

enum BType {
    B1 = 0;
    B2 = 1;
    Unknown = 2;
}

While compiling, I am getting this error:

"Unknown" is already defined in "com.asd". Note that enum values use C++ scoping rules, meaning that enum values are siblings of their type, not children of it. Therefore, "Other" must be unique within "com.asd", not just within "BType".

Is there a workaround for this problem other than using different packages?

user_6900838 · Answer

I believe there is no straightforward way of using the same enum value in the same package but there are two workarounds (link):

Use prefix:

 package com.asd;

 enum AType {
     AType_A1 = 0;
     AType_A2 = 1;
     AType_Unknown = 2;
 }

 enum BType {
     BType_B1 = 0;
     BType_B2 = 1;
     BType_Unknown = 2;
 }

Put the enums in different messages:

 message ATypeMessage{
     enum AType{
         A1 = 0;
         A2 = 1;
         Unknown = 2;
     }
 }

 message BTypeMessage{
     enum BType{
         B1 = 0;
         B2 = 1;
         Unknown = 2;   
     }
 }

user_16334618 · Answer

I don't have enough reputation to post this as a comment, and my suggestion is a hack that might not even work. But have you tried to add the option allow_alias = true; in both enum and use the same value.

Ref: https://developers.google.com/protocol-buffers/docs/proto#enum

Different enums, same value in protobuf

2 Answers