how to debug memory errors

[Era Scarecrow via Digitalmars-d-learn]

On Tuesday, 8 November 2016 at 03:27:32 UTC, Steven Schveighoffer 
wrote:
>>  Err.... that makes no sense... If that's the case why have a 
>> destructor at all?
>
> To free non-GC resources.
>
> http://dlang.org/spec/class.html#destructors
>
> "Furthermore, the order in which the garbage collector calls 
> destructors for unreference objects is not specified. This 
> means that when the garbage collector calls a destructor for an 
> object of a class that has members that are references to 
> garbage collected objects, those references may no longer be 
> valid. This means that destructors cannot reference sub 
> objects."

  Hmmm.. I had the impression that if something was referenced by 
another object, then it couldn't be collected, so sub-objects 
shouldn't/couldn't be collected until the object holding them was 
dealt with (since it holds a reference).

  Although I suppose it's possible to rush in to the deepest 
levels and start collecting there first on objects presumed to be 
unneeded, but that just _feels_ wrong.