var arr = std.mem.zeroes([30_000]u8);

P.S: Not a loop. The implementation of std.mem.zeroes for an non-sentineled array is:

  return [_]info.child{zeroes(info.child)} ** info.len;

Which in this case will be equivalent to:

  return [_]u8{0} ** 30_000;

Which uses the comptime-only `*` operator to expand the single-item u8 array with value 0 into an array of 30k 0s.

That sounds like a loop.