Destructors calling sequence

[Adam D. Ruppe]

In this specific case, you can force a collection at the end of 
main()


void main() {
	auto b = new B;
	a = new A;

	import core.memory;
	GC.collect();
}

The gc runs automatically at the end of the program, but at that 
point, both b and a are gone, so the gc just gets to it as soon 
as it can. Manually calling collect after you're done with b but 
before the program ends (so a is still in use) it should do it in 
order.

But, generally, if you want to rely on destructors at all, you 
have to use structs, or at least destroy(). They might never run 
with classes and the order is undefined - it all depends on when 
and if the GC ever actually grabs it.

Thought a struct at module scope might never run its destructor 
at all...