Deprecate from_slice in favor of the new from_bytes fn

fixed-hash/src/hash.rs

@@ -161,12 +161,28 @@ macro_rules! construct_hash {
 			}
 
 			/// Convert a slice of bytes of length `len()` to an instance of this type.
+			#[deprecated(
+				since = "0.3.0",
+				note = "unconventional API without proper bounds checking, use `from_bytes` instead"
+			)]
 			pub fn from_slice(src: &[u8]) -> Self {
 				let mut r = Self::zero();
 				r.clone_from_slice(src);
 				r
 			}
 
+			/// Create a new fixed-hash from the given slice `src`.
+			/// 
+			/// # Panics
+			/// 
+			/// If the length of `src` and the number of bytes in `Self` do not match.
+			pub fn from_bytes(src: &[u8]) -> Self {
+				assert_eq!(src.len(), $n_bytes);
+				let mut ret = Self::zero();
+				ret.assign_from_slice(src);
+				ret
+			}
+
 			/// Copy the data of this object into some mutable slice of length `len()`.
 			pub fn copy_to(&self, dest: &mut [u8]) {
 				let min = $crate::core::cmp::min($n_bytes, dest.len());