Hi, I didn’t find a way to define BGL adjacency_list without property pointer on edges. I suppose it’s a bug. It’s edge_descriptor is defined as follows: typedef detail::edge_desc_impl edge_descriptor; and template class edge_desc_impl : public edge_base { typedef edge_desc_impl self; typedef edge_base Base; public: typedef void property_type; inline edge_desc_impl() : m_eproperty(0) {} inline edge_desc_impl(Vertex s, Vertex d, const property_type* eplug) : Base(s,d), m_eproperty(const_cast(eplug)) { } property_type* get_property() { return m_eproperty; } const property_type* get_property() const { return m_eproperty; } // protected: property_type* m_eproperty; }; I think that edge_descriptor should be derived directly from edge_base. Regards, Roman.