Cameleon: Stricter Alternative Implementation of VariantN

[Per Nordlöw via Digitalmars-d-learn]

On Tuesday, 22 September 2015 at 09:57:58 UTC, Kagamin wrote:
>> - Do I have to call some GC-logic in order to make the GC 
>> aware of the new string-reference in `opAssign`?
>
> Make sure your struct is always sizeof(void*)-aligned.

How does the GC know if the data block contains a reference 
(pointer) or value type? Does it try to follow that pointer 
either way!?