Synchronized object must not be deleted. causes useless error message

[Frits van Bommel]

BCS wrote:
> this
> 
> auto o = new Object;
> synchronized(o)
>     delete o;
> 
> causes a runtime error:
> 
> Assertion failure: 'h->monitor" on line 99 in file 'internal\monitor.c'

So what would you prefer to happen?

Short version of the problem: because of the synchronized block you're 
accessing a dangling pointer to o.

Long version: When you exit a synchronized block, it needs to unlock the 
monitor associated with the object. I guess before the object is deleted 
the monitor pointer is set to null (like the vtable pointer), which is a 
good thing because otherwise you'd be accessing invalid memory without 
knowing it.
You're still accessing invalid memory of course, since the monitor 
pointer is now itself in invalid memory, but at least it's been detected 
and you're told about it.