Feedback on Átila's Vision for D

[Paulo Pinto]

On Sunday, 20 October 2019 at 17:11:27 UTC, Meta wrote:
> On Sunday, 20 October 2019 at 09:31:34 UTC, Max Samukha wrote:
>> [...]
>
> Interfaces in D do not have any state, i.e., they're not 
> allowed to declare member variables that implementing classes 
> inherit, and they don't define any implementation for 
> implementing classes to inherit - they just define the 
> interface (this has recently changed in Java now that 
> interfaces can define methods with a default implementation, 
> thus Java now provides a way to disambiguate if two different 
> interfaces declare default methods with the same name).
>
> [...]

They don't carry state, but they surely carry semantics hence why 
some languages allow to clarify the implementations.

Because passing implementation B to a method expecting 
implementation A can lead to hard to track down errors.