[plorkyeran]

2-5x faster than both abseil's b+tree and std::map means that abseil's b+tree had to be the same performance as std::map for the tested workload. This is... very unusual. I have only ever seen it be much faster or moderately slower.

[sedatk]

Not necessarily. Insert could be 5x faster in one, and 2x faster in another, and there would still be orders of magnitude difference between both. 2x-5x is a long range.