best container to copy to from boost::multi_index

Using boost::multi_index::multi_index_container

Once I get the projected sequences, I will need to take the set_intersection of them.

What would be the best container to copy the projection to, in order to take the set_intersection?

EDIT: "Best" as in most efficient.

set_intersection just takes iterators, and when in doubt, a vector is your best bet.
The vectors need to be sorted of course.