/// `xor` bitwise operator
/// @access public
/// @param {Number} $x - first value
/// @param {Number} $y - second value
/// @return {Number}
/// @require {function} power
/// @require {function} order-args
/// @require {function} binary-length
/// @example scss
/// $value: bw-xor(42, 48);
/// // 26
@function bw-xor($x, $y) {
  $args: order-args($x, $y);
  $x: nth($args, 1);
  $y: nth($args, 2);
  $b: binary-length($x);
  $res: 0;

  @for $i from 0 through $b {
    $h: power(2, $i);
    $res: $res + $h * (((floor($x / $h) % 2) + (floor($y / $h) % 2)) % 2);
  }

  @return $res;
}