I am looking for a bidirectional container. Requirement Detail: I need to build a data base where by giving the key i should be getting the list of values. And vice versa [i.e By giving One Value get the list of keys] Eg: For Getting the stacks [SHOULD be in same sequence] Given an element id -11 stacks should be 5, 7 & 4 [Same sequence] For eid id 16 - stacks ids - 5, 2 & 7 And for the other way... Given the stack id 5 eids should be - 11, 16, 7 & 12 [Not necessary to be in same sequence] For stack id 4 - eids- 11 & 12 Please let me know if i could achieve this requirement by using one boost container Any help in this regard would be highly appriocated Regards, UJ