[akoboldfrying]

True, but if you always keep a pair of adjacent pointers where before you would have kept just the first, efficient deletion and insertion come back. (You could even go the whole hog and encapsulate this pair as a new WidePointer type, with operator++() and operator--() internally operating on both, etc.)

This will likely be a small constant factor slower for some operations, of course, but if you need bidi traversal and node values are small compared to pointers, it's a solid space savings -- and the lower cache utilisation resulting from that savings may even make it a speed win overall.