I'm considering using the Boost Graph Library to represent binary trees in my application. This will be a planar acyclic directed graph with an adjacency-list representation. The vertices will have properties bundled in an exterior class. A. While building the tree I need to track the depth of each branch and the greatest depth of any branch, that is, the distance from the source vertex to the farthest target vertex. For that I plan to use the distance_recorder. Is that reasonable? Are there pitfalls? Is there a better way? B. I'll need to calculate the total length of the tree by which I mean the sum of all edges. I plan to do a depth-first search and increment a counter with a visitor event point such as discover_vertex. Is that the preferred method? C. On occasion I'll have to swap vertices between two independent trees. My plan is to just swap the bundled properties of each vertex. At first I considered the remove_vertex function but the edges connected to a vertex must be removed first with clear_vertex so before I remove the vertex I'll have to record the source and the target vertices. Then I'll have to add the replacement vertex into the correct position. I can imagine that blowing up in my face. I would appreciate any guidance on this problem. -- Charles Brockman