The sad reality is I have very limited time to devote to evolving the library, so this thing, although in principle simple to implement, has been procrastinated for years now.

Maybe if you sketch the first step that needs to be done here on the list someone will do that and then you can repeat for each step. Whoever would be willing to do this should ask the questions they have here, because there are a number of others on this list who can answer at least some of the questions. A tip to someone willing to do this: Boost Container has emplace support: http://www.boost.org/doc/libs/1_53_0/doc/html/container/move_emplace.html#co... so studying that implementation might be helpful. -- Brian Wood Ebenezer Enterprises http://webEbenezer.net (651) 251-9384