Use nested functions as callbacks with Windows API functions?

[Boris-Barboris]

On Monday, 1 October 2018 at 23:07:29 UTC, spikespaz wrote:
> The problem with the code you have is that the callback needs 
> to be extern (Windows). I don't know how to do that with a 
> "lambda".

Neither do I actually. Apparently it is impossible.
Best I could squeeze out was this:
https://run.dlang.io/is/CpyfW3