Future of contract-based programming in D

[Pierre Krafft via Digitalmars-d]

On Wednesday, 8 April 2015 at 12:13:00 UTC, Kagamin wrote:
> On Wednesday, 8 April 2015 at 12:07:18 UTC, Pierre Krafft wrote:
>> Except for the syntax I can't come up with a problem that 
>> would be better solved using inheritance than using 
>> composition.
>
> How would you interate a collection of widgets without 
> polymorphism, i.e. any generic handling?

I mention the tool I use in the post.
> On Wednesday, 8 April 2015 at 12:07:18 UTC, Pierre Krafft wrote:
> We have interfaces and alias this with @disable so composition 
> is really easy to do.
So use a collection of interface instead of a collection of base 
class. If you squint you could say that what I promote is a way 
of doing inheritance, and I would agree. This is like doing 
inheritance, with a bit worse syntax but with greater flexibility.