[Boost-users] Graph Library Question

Hello, I have a code base which uses adjacency_list as the underlying graph structure. I tried converting from adjacency_list to adjacency_matrix and discovered that adjacency_matrix does not implement the in_edges() non-member function (nor the corresponding iterators). What is the design rationale for including only out_edges() in adjacency_matrix but not in_edges()? Is there a recommended alternative for traversing in_edges for an adjacency_matrix? Thanks, -TAG