The negative array index here is a bit perverse, granted. But the general idea of using structs (with ideally controlled, but hopefully at least well-known, pac

The negative array index here is a bit perverse, granted. But the general idea of using structs (with ideally controlled, but hopefully at least well-known, packing) is surprisingly common, in my experience. I've seen it used for defining binary file and wire formats (which is perhaps somewhat dodgy but there you have it) and, perhaps more appropriately, for EEPROM layouts and the like in embedded systems.