Ordered set with lower_bound

[Igor Ribeiro Sucupira]

Hi.

I need some ordered set that allows me to "search and then iterate"
efficiently. In other words, I need this functionality:
http://www.cplusplus.com/reference/stl/set/lower_bound/

After looking at the documentation for gb_sets and ordsets, I have
concluded that Erlang does not provide that functionality and I'll
have to roll my own. Is it the right conclusion?  :-)

Thanks.
Igor.