Make FixedSizeArray an unsafe trait

Author: alevy

src/libcore/array.rs

@@ -35,14 +35,14 @@ use slice::{Iter, IterMut, SliceExt};
 ///
 /// This trait can be used to implement other traits on fixed-size arrays
 /// without causing much metadata bloat.
-pub trait FixedSizeArray<T> {
+pub unsafe trait FixedSizeArray<T> {
     /// Converts the array to immutable slice
     fn as_slice(&self) -> &[T];
     /// Converts the array to mutable slice
     fn as_mut_slice(&mut self) -> &mut [T];
 }
 
-impl<T, A: Unsize<[T]>> FixedSizeArray<T> for A {
+unsafe impl<T, A: Unsize<[T]>> FixedSizeArray<T> for A {
     #[inline]
     fn as_slice(&self) -> &[T] {
         self