Newbie initial comments on D language - destructor usage

[BCS]

Reply to Edward,

> I have a small nit having to do with a general comment which perhaps I
> did not really understand. In the documentation on class destructors I
> read:
> 
> "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 objects, those references are no longer valid. This means that
> destructors cannot reference sub objects. This rule does not apply to
> auto objects or objects deleted with the DeleteExpression."
> 
> This comment makes perfect sense up to the last sentence. Except for a
> 'scope' class a destructor can not possibly know how it is being
> called so if someone can explain to me how a destructor can know when
> it is OK to reference sub-objects or not, I would love to hear about
> it.

Careful use of manual memory management?