Nabeel

It is a good quality of live improvement, I can't think of a possible downside

This sounds pretty familiar to C# way for defining setters and getter. My problem with this RFC that it discourage code decoupling and separation of responsibilities. I know this is just an example use case, but an object shouldn't know how values should look like, it should be a responsibility of another component.

The 'use' statement clarifies the scope for me. So a proposal like this could have the side effect of mixing scope which would lead to a confusing code.

It looks pretty much the exact function as abstract class. I still think interfaces/contracts should not include any concrete implementation