This is doable via this trick: https://github.com/protocolbuffers/protobuf/blob/ae0129fcd0128b411c968d9a21eb93a5d0253ddf/upb/wire/eps_copy_input_stream.h#L241

This is doable via this trick: https://github.com/protocolbuffers/protobuf/blob/ae0129fcd0128b411c968d9a21eb93a5d0253ddf/upb/wire/eps_copy_input_stream.h#L241 https://github.com/protocolbuffers/protobuf/blob/ae0129fcd01...