Ansi C int16_t reference to int8_t array

Question

I'm stuck with the above problem. Having an int8_t array:

int8_t i8array[3];
i8array[0] = 10;
i8array[1] = 15;
i8array[2] = 100;

And I want to not just convert but also reference an int16_t onto i8array[1]. So I want a new variable i16var, which is an int16_t with the value of 15<<8+100 = 3940.

And if I change i16var to 3941, it should change i8array's item#2 from 100 to 101.

Does ansi C has this facility? I had tried many things, and even in here, I just found answers for converting between these types.

Answer 1

Alignment and endian are the key issues. The below should handle the alignment issue, and maybe the endian one. Good luck. Do not advise the coding approach.

int main(void) {
  union {
    struct {
      int8_t dummy;
      int8_t i8array[3];
    } view1;
    struct {
      int16_t dummy;
      int16_t i16var;
    } view2;
  } u;

  u.view1.i8array[0] = 10;
  u.view1.i8array[1] = 15;
  u.view1.i8array[2] = 100;
  printf("%d\n", htons(u.view2.i16var));
  u.view2.i16var = htons(3941);
  printf("%d\n", u.view1.i8array[2]);
  return 0;
}

Output

3940
101