Casting struct into int

Question

Is there a clean way of casting a struct into an uint64_t or any other int, given that struct in <= to the sizeof int? The only thing I can think of is only an \'ok\' sol

Answer 1

I've just hit the same problem, and I solved it with a union like this:

typedef union {
    struct {
        uint8_t field: 5;
        uint8_t field2: 4;
        /* and so on... */
    } fields;
    uint32_t bits;
} some_struct_t;

/* cast from uint32_t x */
some_struct_t mystruct = { .bits = x };

/* cast to uint32_t */
uint32_t x = mystruct.bits;

HTH, Alex