auto buf = array(new ubyte[j.toString().length+4]);
  size_t index = 0;
  buf.write!uint(cast(uint)buf.length, &index);

  buf.put(j.toString()); // Leaves buf as [0,0,0,0]
  writeln(buf);

  foreach (c; j.toString()) { // Working as intended
    buf.write!char(c, &index);
  }