feat: init commit, copied from crate chacha20-poly-aead

src/as_bytes.rs

@@ -0,0 +1,43 @@
+// Copyright 2016 chacha20-poly1305-aead Developers
+//
+// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
+// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
+// http://opensource.org/licenses/MIT>, at your option. This file may not be
+// copied, modified, or distributed except according to those terms.
+
+use std::mem;
+use std::slice;
+
+pub unsafe trait Safe {}
+
+pub trait AsBytes {
+    fn as_bytes(&self) -> &[u8];
+    fn as_mut_bytes(&mut self) -> &mut [u8];
+}
+
+impl<T: Safe> AsBytes for [T] {
+    #[inline]
+    fn as_bytes(&self) -> &[u8] {
+        unsafe {
+            slice::from_raw_parts(self.as_ptr() as *const u8,
+                                  self.len() * mem::size_of::<T>())
+        }
+    }
+
+    #[inline]
+    fn as_mut_bytes(&mut self) -> &mut [u8] {
+        unsafe {
+            slice::from_raw_parts_mut(self.as_mut_ptr() as *mut u8,
+                                      self.len() * mem::size_of::<T>())
+        }
+    }
+}
+
+unsafe impl Safe for u8 {}
+unsafe impl Safe for u16 {}
+unsafe impl Safe for u32 {}
+unsafe impl Safe for u64 {}
+unsafe impl Safe for i8 {}
+unsafe impl Safe for i16 {}
+unsafe impl Safe for i32 {}
+unsafe impl Safe for i64 {}