In one word: Immutability On 30 July 2012 20:20, Fabrizio Giudici <[email protected]>wrote:
> On Mon, 30 Jul 2012 21:07:05 +0200, Ricky Clarkson < > [email protected]> wrote: > > What hole do you see in Scala and C# if covariance and contravariance open >> holes in type safety? There may well be a problem I don't know of. >> > > In Java if you have a List<String> and you can access it as a > List<Object>, you can put any object inside it: > > List<String> ls = new ArrayList<String>(); > List<Object> lo = ls; // illegal in Java, suppose it is ok just for now > > lo.add(new Date()); > String s = ls.get(0); // ClassCastException at runtime. > > > I don't know about C# and Scala: so somebody please tell me how the > problem above is avoided. > > > > -- You received this message because you are subscribed to the Google Groups "Java Posse" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/javaposse?hl=en.
