Determine if an iterator is on the trailing edge of a node constexpr bool is_trailing(stlab::forest_edge e) (1) template <class I> auto is_trailing(const I & i) (2) (1) constexpr bool is_trailing(stlab::forest_edge e) MISSING Parameters stlab::forest_edge e (2) template <class I> auto is_trailing(const I & i) MISSING Parameters const I & i