Redis-like SortedSet in C#

Question

Unlike the SortedSet<T> or SortedDictionary<T> from BCL, The Sorted Sets from Redis is much more powerful.

• It allows access by member, quite like dictionary
• Sequence is determined on score, a different field from member and allows same value
• allows to get the min/max value with acceptable time-complexity

I don't want to combine Dictionary + SortedSet to achive my goal.

I am looking at C5 library, not quite sure which class is the best for me.

UPDATE: Finally I found this, matching my requirement very well.