The problem at hand, AFAICT, is input validation in an exceptions-verboten environment, which becomes a PITA once instance construction is underway. Inviting t

The problem at hand, AFAICT, is input validation in an exceptions-verboten environment, which becomes a PITA once instance construction is underway. Inviting the question: why not move that validation to a manager class that validates the inputs and returns the desired instance, or a suitable error indication if naughty?