On Jul 16, 2008, at 6:24 PM, Joshua Perry wrote:
A function like you mention (maybe vector<OrderPtr> Customer::GetUnfulfilledOrders( void ); ) could return an vector or custom collection with 0 elements, however with a function like OrderPtr Customer::GetOrder(int ordern); to me it feels natural to throw an exception.
I think this is more like a find function, so you could return an iterator to the appropriate element, and return a one-past-the-end iterator if the order number wasn't found. In your example, you're effectively trying to run a find and then return a dereferenced result. I guess that you are trying to hide any container-ness about the order system, so either returning an order reference or throwing is probably better, but only if you expect the user to never try entering invalid order numbers. If entering invalid numbers is a standard occurrence (pre-checking is too hard and/or not expected), then it wouldn't be a post-condition violation, and a null-pointer should be returned instead. -- Daryle Walker Mac, Internet, and Video Game Junkie darylew AT hotmail DOT com