What would be the consequence of implementing interfaces as fat pointers ?

[Daniel Murphy]

"deadalnix"  wrote in message news:jizqsnuigdsvxhtcsshl at forum.dlang.org...

> All is in the title.
>
> This is becoming increasingly the norm in new languages. It is much better 
> in term of performances (it avoid cascaded loads to call methods, which 
> can be really costly on modern CPUs), make object themselves smaller.
>
> Would implementing them that way break D code ? What would be the extent 
> of the breakage ?

It could, but we don't have a stable ABI and we don't allow directly casting 
from interface references to classes.  I would be interested to see how the 
performance changes on some interface-heavy D code - and honestly without an 
implementation that shows a big speed bump I don't think this will ever 
happen.