[Boost-users] [BGL] adjacent_vertices strange implementation

hi, as far as i can tell the adjacent_vertices function in adjacency list (as well as the inv_adjacent_vertices counterpart) simply wraps around the out_edge (in_edge) function. this differs from what i would expect from a function returning adjacent vertices, since in my notion a set of adjacent vertices shouldn't contain duplicate entries, which the current implementation does have when used with parallel edges. any good reason for that (or does my definition of adjacent vertices differ from everybody else's)? greetings moritz