Would it be possible to add binary_search and partition_point and friends on Slice?

Particular use case I have is an optimization of retain. I currently have index_map.retain(|_, v| foo(&*v) < bar) which works correctly. I happen to know that this index_map is sorted by foo(&*v). I think it would be more efficient to do let cut = index_map.partition_point(foo(&*v) < bar); index_map.truncate(cut) (adjusted for off by one errors). But did not see the tools to do so.