#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
#[derive(TyEncodable, TyDecodable, HashStable)]
pub enum ProjectionElem<V, T> {
#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
#[derive(TyEncodable, TyDecodable, HashStable)]
pub enum ProjectionElem<V, T> {