How to translate the following C++ serialization code to golang equivalent

[Chan Lewis]

Let's say I have a message:

```

message Meta {
  string a = 1;
  int64 b= 2;
}

```

Somebody serializes the message with C++ like this:

```cpp

Meta meta;

char header_and_meta[meta_size];

::google::protobuf::io::ArrayOutputStream arr_out(header_and_meta, meta_size);

::google::protobuf::io::CodedOutputStream coded_out(&arr_out);

meta.SerializeWithCachedSizes(&coded_out);

 ```

Now I need to translate above code to golang equivalent code, but I don't see equivalent struct in golang. I use proto.Marshal(meta), but the result of type []byte, is not totally same as data within header_and_meta

Anything wrong ?

[Chan Lewis]

It turns out that the output bytes for proto3 are different from those for proto2. I fix it now.