// A subroutine that writes its `readonly` array argument: the argument is a
// reference to the caller's array, which a `readonly` one may not change.
OPENQASM 3.1;
include "stdgates.inc";
def scale(readonly array[int[8], #dim = 1] a) {
  a[0] = 2 * a[0];
}
array[int[8], 2] weights = {1, 2};
qubit[1] q;
scale(weights);