Thread: Is this a valid union definition?

I'm trying to write a function to serialise data within a struct so I can send it over UDP by defining a union to map the struct to a byte array:

Code:

typedef struct scan_data_t
{
     long range;
     float angle;
} scan_data_t

typedef union udp_packet_t
{
    struct data_t
    {
        char command;
        int num_scans;
        scan_data_t *scans;
    } data;
    char *udp;
} __attribute__((packed)) udp_packet_t;

If you want to serialise data, then it can't contain any pointers.

Having solved that, you would declare
char udp[sizeof(data)]
as your serialisation member.