It's not a half feature. But yeah, I can see that "engineers" like you don't understand it. The same duck metaphor is stupidly used to criticize interfaces. And

It's not a half feature. But yeah, I can see that "engineers" like you don't understand it. The same duck metaphor is stupidly used to criticize interfaces. And then you have everyone trying to use hacks to get around this issue, usually people who do understand what "design by contract" is, but for some reason don't want to leave Ruby. Just google "ruby interface" and see for yourself. This problem won't go away until people like you stop spreading lies to justify the lack of features (eg: "Hurr durr, Java needs interfaces because it's too rigid, Ruby doesn't need that, lol!").