Comment by spacechild1

One example that comes to my mind is libopus: https://github.com/xiph/opus

If you have structs that might need to be extended, you can use "versioned structs". One popular technique is to include the struct size as the first field. The struct size is set to `offsetof(mystruct, lastmember) + sizeof(lastmember)` and the receiver of the struct can use this to check if a member exists. The ARA API is a good example: https://github.com/Celemony/ARA_API/blob/65ec5c43b943a48cb54...