@function be-close-to($this, $precision) {
  $actual: actual();
  $when: false;

  @if type-of($actual) == "number" {
    $when: abs($this - $actual) < (bc-util-power(10, -$precision) / 2);
  } @else {
    $when: error("type", "The `be-close-to` matcher is only for numbers");
  }

  @return should("be close to", $this, $when);
}