Silent error when using hashmap

[ketmar via Digitalmars-d]

FatalCatharsis wrote:

> On Wednesday, 26 July 2017 at 16:39:15 UTC, ketmar wrote:>
>> 'cause `WM_CREATE` is not the first message window receiving. check if 
>> hwnd is in hash with `in` first.
>
> I figured this was the case. WM_NCCREATE is probably sent first and the 
> lookup fails. I'm more concerned with why there was no exceptions/debug 
> output of any kind.

'cause windows' event handler called from darkes depths of windows code, 
and D just can't make sense of the stack to unwind it properly and to show 
you error message and stack trace. never ever rely on getting proper stack 
traces for exceptions thrown in windows callbacks: it *may* work sometimes, 
but it is not guaranteed.