[multi_index] feature request In my code I often use collections of noncopyable objects and yet I need to have them indexed. The usual solution is to store pointers to the objects in the index (be it a std::set/map or boost::multi_index). This leads to two allocations: the first for the object and the second for the index node. For me it would be more natural and effective to embed the index node in the object, so that the container is obviated from allocating nodes and only maintains indexes. This also would make all container operations nothrow, since element insertion and removal requires only node pointer manipulations and using the comparer object which is typically nothrow. In my work I use my own intrusive_list which has proved itself quite useful and effective. The syntax is: struct noncopyable_object; typedef intrusive_list<noncopyable_object> list; struct noncopyable_object : list::node // embed the list node in the class { // ... }; Will such a feature ever make it to multi_index? -- Maxim Yegorushkin <firstname.lastname@gmail.com>