[Issue 15984] Interface contracts retrieve garbage instead of parameters

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15984

--- Comment #5 from Stewart Gordon <smjg at iname.com> ---
(In reply to Denis Shelomovskij from comment #4)
> Thanks, I still can't remember how does current implementation of D
> contracts work.

It looks like it calls the base class's in contract and, if that fails, calls
the derived class's in contract?

>> But even better would be to add debugging output to I's in contract.
> 
> Parameter contains garbage, I don't think there is any need to print it.

How do you establish that the parameter contains garbage (as opposed to any
other possible cause of what we're observing) without printing it?

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