__attribute__(packed) structs with an enum at the front indicating their type. The receivers use a switch to figure out which sub-message to interpret the stric

__attribute__(packed) structs with an enum at the front indicating their type. The receivers use a switch to figure out which sub-message to interpret the strict as... It isn't pretty and you better be able to control the rollout of both sides because backwards compatibility will not be a thing. But I'll take it over a giant pile of code generation in many circumstances