add derive Hash to Scalar, MontgomeryPoint and CompressedEdwardsY

src/edwards.rs

@@ -150,7 +150,7 @@ use backend::vector::scalar_mul;
 ///
 /// The first 255 bits of a `CompressedEdwardsY` represent the
 /// \\(y\\)-coordinate.  The high bit of the 32nd byte gives the sign of \\(x\\).
-#[derive(Copy, Clone, Eq, PartialEq)]
+#[derive(Copy, Clone, Eq, PartialEq, Hash)]
 pub struct CompressedEdwardsY(pub [u8; 32]);
 
 impl ConstantTimeEq for CompressedEdwardsY {

src/montgomery.rs

@@ -65,7 +65,7 @@ use zeroize::Zeroize;
 
 /// Holds the \\(u\\)-coordinate of a point on the Montgomery form of
 /// Curve25519 or its twist.
-#[derive(Copy, Clone, Debug)]
+#[derive(Copy, Clone, Debug, Hash)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct MontgomeryPoint(pub [u8; 32]);
 

src/scalar.rs

@@ -182,7 +182,7 @@ type UnpackedScalar = backend::serial::u32::scalar::Scalar29;
 
 /// The `Scalar` struct holds an integer \\(s < 2\^{255} \\) which
 /// represents an element of \\(\mathbb Z / \ell\\).
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Hash)]
 pub struct Scalar {
     /// `bytes` is a little-endian byte encoding of an integer representing a scalar modulo the
     /// group order.