Exactly. This is in fact done in some languages to mark generations for garbage collection.
Again, I have only used Java a little bit, but I don't see how a language that allows you do pointer arithmetic (flipping one of the bits in the pointer), and then de-reference the modified pointer, could be type safe.…
Their implementation is in Java. I am not too familiar with Java, but I don't think that is possible; it's a tradeoff of memory efficiency for type safety.
Exactly. This is in fact done in some languages to mark generations for garbage collection.
Again, I have only used Java a little bit, but I don't see how a language that allows you do pointer arithmetic (flipping one of the bits in the pointer), and then de-reference the modified pointer, could be type safe.…
Their implementation is in Java. I am not too familiar with Java, but I don't think that is possible; it's a tradeoff of memory efficiency for type safety.