> The only good reason to use packed structures is when you need to map some memory (e.g. hardware registers exposed to memory) bit by bit to a structure.
Another common reason is when two CPUs of different architecture need to access the same structure in memory. E.g. you have a RiscV and an Arm64 processor in the same system, sharing memory. Or you read structured binary data from disk and need to specify an exact layout.
Another common reason is when two CPUs of different architecture need to access the same structure in memory. E.g. you have a RiscV and an Arm64 processor in the same system, sharing memory. Or you read structured binary data from disk and need to specify an exact layout.