Question on Interface.

[evilrat]

On Wednesday, 7 August 2013 at 07:30:52 UTC, SteveGuo wrote:
>> if D would allow this - what is then the difference between a 
>> class with your methods as virtuals + your string?
>>
>> interface are for loosier coupling then classes - thats why 
>> only declerations not implementations (like your string) are 
>> allowed, same goes to Java and C# (and i think most other 
>> interface having languages)
>
> But classes cannot enforce its successor to do something. May 
> introduce a new keyword "enforce"?

what? O_o
let me explain, abstract class requires its successors to 
implement all methods, but may have fields.
class successors *always* do something, either their methods has 
derived behavior or overridden ones. so does interface, if you 
has class derived from interface then its successors may or may 
not override its methods.