On Tue, 2011-11-01 at 12:15 -0700, Cromwell Enage wrote:

I've been studying the tree proposal to see how I could write adaptors in my tree_node library (now at version 0.2 in the sandbox) that conform to the current concepts. Is there anything in the proposal that is analogous to a PairAssociativeContainer? My tree_node library defines an AssociativeTreeNode concept and a couple of models that I've found to be useful, e.g. for implementing decision tree learning algorithms.

My reading of the hierarchical container draft is that associative container functionalities (and other varieties of container interfaces) actually live in the cursor: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2101.html#tr.cursor... I'm not entirely sure about the relative merits of that versus defining a parallel zoology of Hierarchical Containers that is basically isomorphic to the traditional Container hierarchy, and leaving the cursor definition more lightweight: perhaps just "iterator plus parent(), begin() and end()", or alternatively not having a separate cursor type, and simply having traditional iterators over children at any given node.