[boost] Interest in O(log n) linear list?

The STL contains vector, which has O(1) lookup and O(n) insertion. It also has list, which has O(n) lookup and O(1) insertion. There is also a third type of container, which doesn't exist in the STL, which has O(log n) lookup and O(log n) insertion. (For those who have read Knuth's TAOCP, it's a balanced tree with the RANK field). AFAIK, there is no well-known name for this structure, but a linear list with both operations fairly fast seems a useful item to have. Any interest? Thanks, Stephen Dolan