> Also, I'm fairly certain synchronizing isn't an issue because there's nothing to synchronize on since the data structures are immutable. Am I understanding yo

> Also, I'm fairly certain synchronizing isn't an issue because there's nothing to synchronize on since the data structures are immutable. Am I understanding you correctly? No -- I'm referring to synchronization on the heap itself (think new()/delete()). Multiple threads allocating memory need to synchronize in order to avoid trampling on each other. You can't just get rid of synchronization entirely.