public function subtract(Utils_CurrencyField_Value $other, $report_error = true)
{
if ($this->get_currency_id() == $other->get_currency_id()) {
$this->subtract_amount($other->get_amount());
} elseif ($report_error) {
$msg = "Can't subtract two values of different currencies.";
throw new Utils_CurrencyField_CurrencyMismatchException($msg);
}
}
public function add(Utils_CurrencyField_Value $value)
{
$sum = $this->get_currency_sum($value->get_currency_id());
$sum->add($value);
}