hashers: impl Clone

This follows the C-COMMON-TRAITS guidelines, and aligns with
std::hash::DefaultHasher.

Author: newAM

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Added
 
 - Added `Debug` implementations to hashers.
+- Added `Clone` implementations to hashers.
 
 ### Changed
 

src/fnv.rs

@@ -8,7 +8,7 @@ const PRIME: u32 = 0x1000193;
 /// Specifically this implements the [FNV-1a hash].
 ///
 /// [FNV-1a hash]: https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function#FNV-1a_hash
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct FnvHasher {
     state: u32,
 }

src/murmur3.rs

@@ -4,15 +4,15 @@ use core::slice;
 use crate::Hasher as _;
 
 /// 32-bit `MurmurHash3` hasher
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct Murmur3Hasher {
     buf: Buffer,
     index: Index,
     processed: u32,
     state: State,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 struct State(u32);
 
 #[derive(Debug, Clone, Copy)]