1 // This is an example of how to handle 'union' style messages 2 // with nanopb, without allocating memory for all the message types. 3 // 4 // There is no official type in Protocol Buffers for describing unions, 5 // but they are commonly implemented by filling out exactly one of 6 // several optional fields. 7 8 syntax = "proto2"; 9 10 message MsgType1 11 { 12 required int32 value = 1; 13 } 14 15 message MsgType2 16 { 17 required bool value = 1; 18 } 19 20 message MsgType3 21 { 22 required int32 value1 = 1; 23 required int32 value2 = 2; 24 } 25 26 message UnionMessage 27 { 28 optional MsgType1 msg1 = 1; 29 optional MsgType2 msg2 = 2; 30 optional MsgType3 msg3 = 3; 31 } 32 33
