"External interfaces" or "Interface maps"

[Hxal]

Andrei Alexandrescu Wrote:
> The question is, to what extent would post-factum interfaces 
> enable or improve idioms?

I was really looking at the possibility of adapting objects to interfaces
without additional wrapper allocation, but with dynamically allocated
vtables that makes little sense.
 
> Also, it might be of interest to you that I implemented compound types 
> as described by Buchi and Weng, see 
> https://eprints.kfupm.edu.sa/31204/1/31204.pdf), and also straight 
> structural casts. These should cover at least a few idioms that could 
> use post-factum interfaces. I haven't released the code to public 
> attention because I haven't gotten around to it.

Being able to declare void foo (IReadable & ISeekable device) sounds
wicked cool. But I don't have interface heavy code myself,
someone who does would need to judge if it can simplify code in practice.