Derive Default for enums (#2035)

The feature is stable since Rust 1.62.

Author: newpavlov

elliptic-curve/src/dev.rs

@@ -447,12 +447,13 @@ impl IsHigh for Scalar {
 }
 
 /// Example affine point type
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Default, Debug, Eq, PartialEq)]
 pub enum AffinePoint {
     /// Result of fixed-based scalar multiplication.
     FixedBaseOutput(Scalar),
 
     /// Identity.
+    #[default]
     Identity,
 
     /// Base point.
@@ -506,12 +507,6 @@ impl ConditionallySelectable for AffinePoint {
     }
 }
 
-impl Default for AffinePoint {
-    fn default() -> Self {
-        Self::Identity
-    }
-}
-
 impl DefaultIsZeroes for AffinePoint {}
 
 impl From<NonIdentity<AffinePoint>> for AffinePoint {
@@ -569,12 +564,13 @@ impl TryFrom<AffinePoint> for NonIdentity<AffinePoint> {
 }
 
 /// Example projective point type
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Default, Debug, Eq, PartialEq)]
 pub enum ProjectivePoint {
     /// Result of fixed-based scalar multiplication
     FixedBaseOutput(Scalar),
 
     /// Is this point the identity point?
+    #[default]
     Identity,
 
     /// Is this point the generator point?
@@ -620,12 +616,6 @@ impl ConditionallySelectable for ProjectivePoint {
     }
 }
 
-impl Default for ProjectivePoint {
-    fn default() -> Self {
-        Self::Identity
-    }
-}
-
 impl DefaultIsZeroes for ProjectivePoint {}
 
 impl From<AffinePoint> for ProjectivePoint {

password-hash/src/encoding.rs

@@ -6,7 +6,7 @@ use base64ct::{
 };
 
 /// Base64 encoding variants.
-#[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+#[derive(Copy, Clone, Default, Debug, Eq, PartialEq, PartialOrd, Ord)]
 #[non_exhaustive]
 pub enum Encoding {
     /// "B64" encoding: standard Base64 without padding.
@@ -16,6 +16,7 @@ pub enum Encoding {
     /// 0x41-0x5a, 0x61-0x7a, 0x30-0x39, 0x2b, 0x2f
     /// ```
     /// <https://github.com/P-H-C/phc-string-format/blob/master/phc-sf-spec.md#b64>
+    #[default]
     B64,
 
     /// bcrypt encoding.
@@ -47,12 +48,6 @@ pub enum Encoding {
     ShaCrypt,
 }
 
-impl Default for Encoding {
-    fn default() -> Self {
-        Self::B64
-    }
-}
-
 impl Encoding {
     /// Decode a Base64 string into the provided destination buffer.
     pub fn decode(self, src: impl AsRef<[u8]>, dst: &mut [u8]) -> Result<&[u8], B64Error> {