operator - method

@override Quantity operator -(dynamic subtrahend)

Override the subtraction operator to manage the Temperature/TemperatureInterval relationship.

• Subtracting a TemperatureInterval returns a TemperatureInterval object.
• Attempting to subtract a Temperature from a TemperatureInterval throws a QuantityException as a physically nonsensical operation.

Implementation

@override
Quantity operator -(dynamic subtrahend) {
  if (subtrahend is TemperatureInterval) {
    final newValueSI = valueSI - subtrahend.valueSI;
    final ur = Quantity.calcRelativeCombinedUncertaintySumDiff(
        this, subtrahend, newValueSI);
    return TemperatureInterval(K: newValueSI, uncert: ur);
  } else if (subtrahend is Temperature) {
    throw const QuantityException(
        'Subtracting a Temperature from a TemperatureInterval is not supported.');
  } else {
    return super - subtrahend;
  }
}