Jonathan M Davis wrote: ... > > Generally, I speaking, I think that having functions which override > functions from a base class and throw if they're used is a bad design. It > may be that it makes perfect sense in some contexts, but generally, I'd > consider it a very bad idea. Personally, I hate it when APIs do that.
I agree, but it's sometimes hard to avoid. For example if you want a composite and component class to have a common interface, some operations won't make sense for components. The alternative to throwing is a no-op or return a null object. Or asserting. > Regardless of whether you consider that a good or bad idea though, there's > no point in adding contracts into it. They don't add anything. If the > feature is supported by the class, then no exception gets thrown. If it > isn't, then an exception gets thrown. All adding asserts in preconditions > does is make it an AssertError instead of whatever kind of exception you're > throwing in the body. It doesn't add anything. > > - Jonathan M Davis True, it only adds AssertError and that could be replaced with regular asserts. Thanks.
