> I've been mucking about a bit more with this whole interface thing. > > So if we make method signatures only enforced on subclasses if the parent > class or method has the interface property... > > ....except private methods, obviously. > > And if we make pre/post conditions and class invariants always enforced... > > ....shouldn't we have private invariants and conditions?
Semi-tangential to the point of your message... With pre/post conditions, a subclass is allowed to weaken the preconditions or strengthen the postconditions. The postcondition is not really a problem since one can always add additional checks. However, if the parent's preconditions apply to the child invariably, it would be rather difficult to make your subclass accept a wider variety of input. I'm not proposing a solution, but rather just a problem to keep in mind. Mike Lambert
