clean up some unsafety in Slicable

substrate/primitives/src/hashing.rs

@@ -20,37 +20,37 @@ use blake2_rfc;
 use twox_hash;
 
 /// Do a Blake2 512-bit hash and place result in `dest`.
-pub fn blake2_512_into(data: &[u8], dest: &mut[u8; 64]) {
+pub fn blake2_512_into(data: &[u8], dest: &mut [u8; 64]) {
 	dest.copy_from_slice(blake2_rfc::blake2b::blake2b(64, &[], data).as_bytes());
 }
 
 /// Do a Blake2 512-bit hash and return result.
 pub fn blake2_512(data: &[u8]) -> [u8; 64] {
-	let mut r: [u8; 64] = unsafe { ::std::mem::uninitialized() };
+	let mut r = [0; 64];
 	blake2_512_into(data, &mut r);
 	r
 }
 
 /// Do a Blake2 256-bit hash and place result in `dest`.
-pub fn blake2_256_into(data: &[u8], dest: &mut[u8; 32]) {
+pub fn blake2_256_into(data: &[u8], dest: &mut [u8; 32]) {
 	dest.copy_from_slice(blake2_rfc::blake2b::blake2b(32, &[], data).as_bytes());
 }
 
 /// Do a Blake2 256-bit hash and return result.
 pub fn blake2_256(data: &[u8]) -> [u8; 32] {
-	let mut r: [u8; 32] = unsafe { ::std::mem::uninitialized() };
+	let mut r = [0; 32];
 	blake2_256_into(data, &mut r);
 	r
 }
 
 /// Do a Blake2 128-bit hash and place result in `dest`.
-pub fn blake2_128_into(data: &[u8], dest: &mut[u8; 16]) {
+pub fn blake2_128_into(data: &[u8], dest: &mut [u8; 16]) {
 	dest.copy_from_slice(blake2_rfc::blake2b::blake2b(16, &[], data).as_bytes());
 }
 
 /// Do a Blake2 128-bit hash and return result.
 pub fn blake2_128(data: &[u8]) -> [u8; 16] {
-	let mut r: [u8; 16] = unsafe { ::std::mem::uninitialized() };
+	let mut r = [0; 16];
 	blake2_128_into(data, &mut r);
 	r
 }