There's an obvious evolution path, namely supporting the rest of node types. Random access should be straightforward, as elements can easily be traversed in a linear fashion much as you're already doing with sequenced nodes --so if you want some clues about that please tell me so. As for the other node types (ordered and hashed) traversal is not that simple, I guess it'd help a lot to see how the built-in visualizers for std::map and stdext::hash_map are doing.
The visualizer offers tree traversal: #tree(head:? size:? left:? right:? skip:?) I tried and succeeded partially, with boost::multi_index::detail::header_holder<boost::multi_index::detail::ordered_index_node<*>,*>{ preview(#("multi_index_container data")) children( #( #tree( head : ; the head node (ordered_index_node_compressed_base*) (ordered_index_node_impl*) (ordered_index_node_trampoline<$T1>*) ($c.member), size : ((multi_index_helper_3<$T2>*)&$c)->node_count, left : left_, right : right_, ; skip null nodes skip : 0 ) : ; node formatting *(multi_index_helper<ordered_index_node<$T1> >*) (ordered_index_node<$T1>*) (ordered_index_node_trampoline<$T1>*) (&$e) ) ) } Out of 3 items, I can see the leaf nodes (left_ and right_) correctly, but the head node is displayed incorrectly. When I add some more items, I still see just 2 or 3 items and the rest is garbage. Perhaps there is something about _compressed_base which needs special treatment? BTW, std::map is visualized by #tree ( head : $c._Myhead->_Parent, skip : $c._Myhead, size : $c._Mysize, left : _Left, right : _Right ) : $e._Myval and stdext::hash_map by #list ( head : $c._List._Myhead->_Next, size : $c._List._Mysize, next : _Next ) : $e._Myval Piece of cake :-) Thanks, Filip