Introducing Nullable Reference Types in C#. Is there hope for D, too?

[Dmitry Olshansky]

On Tuesday, 21 November 2017 at 06:03:33 UTC, Meta wrote:
> On Tuesday, 21 November 2017 at 01:03:36 UTC, Mark wrote:
>> On Monday, 20 November 2017 at 22:56:44 UTC, Walter Bright 
>> wrote:
>>> On 11/20/2017 3:27 AM, Timon Gehr wrote:
>>
>> This blog post seems to summarize the paper he linked to:
>> https://dev.to/rosstate/java-is-unsound-the-industry-perspective
>
> I'm not clear on whether he means that Java's type system is 
> unsound, or that the type checking algorithm is unsound. From 
> what I can tell, he's asserting the former but describing the 
> latter.

The spec describes unsound language, the hole in type-system are 
plugged at VM level by run-time checks.

Also this jawel:

Cat[] cats = new Cat[3];
...
Animals[] animals = cats; // the same array

animals[0] = new Dog();

cats[0].smth(); // ClassCast exception or some such