dear all:

i'm a game developer, and my projects used a lot of multi_index(thanks, it's a great library).

one of main problems of game development is to rank players according to they level. usually we

use boost::interprocess::map for the task. but more, players should know which rank they are and

who is at rank 10000 (for example). these requirements lead to two new methods for map:

iterator find_by_rank(int idx)

int rank(iterator i)

i implemented an argumented rbtree data structure according to "Algorithms and Data Structures "

(see the attachment rank_tree.hpp), and latter i find coutertree which is in boost review schedule.

but IMHO, the best way is to integrate it to multi_index, and if anyone interests, i can do this by some efforts.

yours sincerely