[Boost-users] container with large number of elements and a small number of invalide elements

Hello, I have a need for a container where I can store 10^6 elements of type T (PODs) , a small number of which (say 100) can be invalid elements (ie special value of T) The 100 elements can be randomly distributed throughout the 10^6 elements. The container should be as close to a sequence container as possible. The required usages: 0. invalid elements can be set = 10^6 - 100 1. get number of valid elements in O(1) 2. get the max/min element of all valid elements 3. have a bidrectional iterator that iterators only over valid elements On a separate note, is there a version of multi_array where the number of dimensions is known at runtime? regards,