Hi, I'm currently facing some limitations from flyweight and multi_index. Let's begin with multi_index: I'd want to have a multi_index storing containers, and have one index based on all the contained elements. For example: two vectors [1 2 3] and [3 4] would be indexed as 1 -> [1 2 3] 2 -> [1 2 3] 3 -> [1 2 3] [3 4] 4 -> [3 4] How would you do that ? Flyweight: I'd like to have a scoped flyweight, without tracking, i.e.: { ... // create some elements } // All elements are deleted when leaving the scope. However, currently I didn't see a method to clear the internal container. One way I could do that would be copying - pasting the hashed_factory and adding a clear method. It would be easier to extend the class, just having the private container be protected. Would that be possible to do one a future release ? Or is there another easy way to do so ? Regards, Samuel