[CJefferson]

Nope, intrusive is different. Because this is using an Rc (reference counted pointer) for the forward and backward pointers, these counters are both set to '2', as (almost) everything in a doubly-linked list has two things pointing to it, the thing after and the thing before.

[steveklabnik]

I'm saying you're asking for intrusive ("each node contains the data and two pointers") whereas this list is not intrusive.