Invariants for methods

[bearophile]

Andrei:

> There is a limitation of the current system in that the out contract 
> can't see the scope of the in contract. Walter and I tried to find a 
> solution, but it was technically difficult in the presence of inheritance.

C#4 designers seem to have found a way to implement "old" (Prestate Values) correctly enough, so can't D2 adopt a similar solution?

Bye,
bearophile