Derive Copy and Clone

There is no obvious reason why not to derive `Copy` and `Clone` for
types that use the `impl_newtype_macro`. Derives are less surprising so
deriving makes the code marginally easier to read.

Author: tcharding

secp256k1-sys/src/lib.rs

@@ -133,6 +133,7 @@ impl SchnorrSigExtraParams {
 
 /// Library-internal representation of a Secp256k1 public key
 #[repr(C)]
+#[derive(Copy, Clone)]
 pub struct PublicKey([c_uchar; 64]);
 impl_array_newtype!(PublicKey, c_uchar, 64);
 impl_raw_debug!(PublicKey);
@@ -226,6 +227,7 @@ impl core::hash::Hash for PublicKey {
 
 /// Library-internal representation of a Secp256k1 signature
 #[repr(C)]
+#[derive(Copy, Clone)]
 pub struct Signature([c_uchar; 64]);
 impl_array_newtype!(Signature, c_uchar, 64);
 impl_raw_debug!(Signature);
@@ -313,6 +315,7 @@ impl core::hash::Hash for Signature {
 }
 
 #[repr(C)]
+#[derive(Copy, Clone)]
 pub struct XOnlyPublicKey([c_uchar; 64]);
 impl_array_newtype!(XOnlyPublicKey, c_uchar, 64);
 impl_raw_debug!(XOnlyPublicKey);
@@ -401,6 +404,7 @@ impl core::hash::Hash for XOnlyPublicKey {
 }
 
 #[repr(C)]
+#[derive(Copy, Clone)]
 pub struct KeyPair([c_uchar; 96]);
 impl_array_newtype!(KeyPair, c_uchar, 96);
 impl_raw_debug!(KeyPair);

secp256k1-sys/src/macros.rs

@@ -17,8 +17,6 @@
 #[macro_export]
 macro_rules! impl_array_newtype {
     ($thing:ident, $ty:ty, $len:expr) => {
-        impl Copy for $thing {}
-
         impl $thing {
             /// Like `cmp::Ord` but faster and with no guarantees across library versions.
             ///
@@ -92,14 +90,6 @@ macro_rules! impl_array_newtype {
             }
         }
 
-        impl Clone for $thing {
-            #[inline]
-            fn clone(&self) -> $thing {
-                let &$thing(ref dat) = self;
-                $thing(dat.clone())
-            }
-        }
-
         impl<I> core::ops::Index<I> for $thing
         where
             [$ty]: core::ops::Index<I>,

secp256k1-sys/src/recovery.rs

@@ -21,6 +21,7 @@ use core::fmt;
 
 /// Library-internal representation of a Secp256k1 signature + recovery ID
 #[repr(C)]
+#[derive(Copy, Clone)]
 pub struct RecoverableSignature([c_uchar; 65]);
 impl_array_newtype!(RecoverableSignature, c_uchar, 65);
 

src/key.rs

@@ -56,6 +56,7 @@ use crate::{hashes, ThirtyTwoByteHash};
 /// ```
 /// [`bincode`]: https://docs.rs/bincode
 /// [`cbor`]: https://docs.rs/cbor
+#[derive(Copy, Clone)]
 pub struct SecretKey([u8; constants::SECRET_KEY_SIZE]);
 impl_array_newtype!(SecretKey, u8, constants::SECRET_KEY_SIZE);
 impl_display_secret!(SecretKey);

src/lib.rs

@@ -233,6 +233,7 @@ impl<T: hashes::sha256t::Tag> ThirtyTwoByteHash for hashes::sha256t::Hash<T> {
 }
 
 /// A (hashed) message input to an ECDSA signature.
+#[derive(Copy, Clone)]
 pub struct Message([u8; constants::MESSAGE_SIZE]);
 impl_array_newtype!(Message, u8, constants::MESSAGE_SIZE);
 impl_pretty_debug!(Message);

src/macros.rs

@@ -17,7 +17,6 @@
 #[macro_export]
 macro_rules! impl_array_newtype {
     ($thing:ident, $ty:ty, $len:expr) => {
-        impl Copy for $thing {}
 
         impl AsRef<[$ty; $len]> for $thing {
             #[inline]
@@ -59,14 +58,6 @@ macro_rules! impl_array_newtype {
             }
         }
 
-        impl Clone for $thing {
-            #[inline]
-            fn clone(&self) -> $thing {
-                let &$thing(ref dat) = self;
-                $thing(dat.clone())
-            }
-        }
-
         impl<I> core::ops::Index<I> for $thing
         where
             [$ty]: core::ops::Index<I>,

src/schnorr.rs

@@ -14,6 +14,7 @@ use crate::SECP256K1;
 use crate::{constants, from_hex, impl_array_newtype, Error, Message, Secp256k1, Signing, Verification};
 
 /// Represents a Schnorr signature.
+#[derive(Copy, Clone)]
 pub struct Signature([u8; constants::SCHNORR_SIGNATURE_SIZE]);
 impl_array_newtype!(Signature, u8, constants::SCHNORR_SIGNATURE_SIZE);
 impl_pretty_debug!(Signature);