Is there an alternative to Range Initialization of arrays in C?

I believe it's a simple question: Is there a way to initialize an array with values that are nonzero without using loops?

One way I know is to use Range Initialization to initialize the array with the values I want. For example:

int main()
{
   /* Using Designated Range Initialization*/
   int my_array[10] = {[0 ... 3] = 5, [4 ... 7] = 15, [8 ... 9] = 30};
   /* Using Explicit initialization for each element */
   int other_array[10] = {5, 5, 5, 5, 15, 15, 15, 15, 30, 30};

   return 0;
}

However, this method is just an extension of the GCC compiler, and not part of ISO C. So given this possible non-portability between systems, is there a way to do an array initialization in a similar way? Of course, without using loops.

Also, the method I'm looking for is just beyond the explicit initialization of each element of the array.

Solution

Code needs to explicitly initialize the non-zero array elements.

Could use macro magic if there is a pattern:

#define ONE(x) (x), (x)+1, (x)+2, (x)+3, (x)+4, (x)+5, (x)+6, (x)+7, (x)+8, (x)+9
#define TEN(x) ONE(x),ONE((x)+10),ONE((x)+20),ONE((x)+30),ONE((x)+40), \
    ONE((x)+50),ONE((x)+60),ONE((x)+70),ONE((x)+80),ONE((x)+90)

int main() {
  int count[100] = { TEN(1) };
  printf("%d %d\n", count[0], count[99] );
}

Output

1 100

Example for OP

#define X2(x) (x), (x)
// Note the nested macro
#define X4(x) X2(x), X2(x)
#define X8(x) X4(x), X4(x)
#define X10(x) X8(x), X2(x)
#define X16(x) X8(x), X8(x)
// ....


int main()
{
   int my_array[10] = { X4(5), X4(15), X2(30)};
   printf("%d %d\n", my_array[0], my_array[9] );
   return 0;
}

Output

5 30