/// A vector type optimized for cases where this size is usually 0 (cf. `SmallVector`).
/// The `Option<Box<..>>` wrapping allows us to represent a zero sized vector with `None`,
/// which uses only a single (null) pointer.
-#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
+#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct ThinVec<T>(Option<Box<Vec<T>>>);
impl<T> ThinVec<T> {