Method ShiftCargo

src/cargopacket.cpp:290–301

 */
template <class Taction>
void VehicleCargoList::ShiftCargo(Taction action)
{
	Iterator it(this->packets.begin());
	while (it != this->packets.end() && action.MaxMove() > 0) {
		CargoPacket *cp = *it;
		if (action(cp)) {
			it = this->packets.erase(it);
		} else {
			break;
		}
	}
}

/**
 * Pops cargo from the back of the packet list and applies some action to it.