detecting the absence of optional fields at the receiver

From what I have read, it seams that if I don't send an optional field, the field will have an explicit or implicit value at the receiver. However, will functions like has_ in C++ know that the received message is missing the optional field? --~--~-~--~~~---~--~~

Re: [protobuf] Decimal in json?

Well, it might be as simple as how it is represented in .Net: http://csharpindepth.com/Articles/General/Decimal.aspx Other languages might have different representation, and ranges, so whatever is chosen, there may be cases where the wire format can't be represented in the native type for a