Polymorphic catcalls

[Famous]

On Saturday, 21 April 2012 at 13:52:20 UTC, Kagamin wrote:
> The Little Willy example applies to D just fine. When served 
> wrong drink, Little Willy has little choice but to throw an 
> exception. This seems like a strengthening of a Customer's 
> contract, doesn't it? It doesn't matter how the typecheck is 
> done technically. And this strengthening seems to be inevitable 
> in practice.

It's not inevitable, it's wrong design.

While each square is a rectangle in mathematics this is not
necessarily true in an object oriented model.

Cheers,
Famous