[boost] [interprocess][flat_map/flat_set] provide read access to underlying container

Hi Ion, Sometimes I need to go through all elements in such a container. However, it is know that the number of elements is low, so I unroll the loop manually. In that case I would like to be able to do the following: const T& t1 = flat_set[0u]; const T& t2 = flat_set[1u]; Alternatively, provide a base() function that directly give read access to the underlying container: const T& t1 = flat_set.base()[0u]; Comments? -Thorsten