diff --git a/src/lib.rs b/src/lib.rs
index 47acf336..bcfdc62d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -92,9 +92,7 @@
 #![deny(missing_docs)]
 #![deny(warnings)]
 #![feature(const_fn)]
-#![feature(const_unsafe_cell_new)]
 #![feature(core_intrinsics)]
-#![feature(shared)]
 #![feature(unsize)]
 #![no_std]
 
diff --git a/src/string.rs b/src/string.rs
index d0cd07ee..f1cf88c9 100644
--- a/src/string.rs
+++ b/src/string.rs
@@ -426,6 +426,26 @@ where
     }
 }
 
+impl<A> AsRef<str> for String<A>
+where
+    A: Unsize<[u8]>,
+{
+    #[inline]
+    fn as_ref(&self) -> &str {
+        self
+    }
+}
+
+impl<A> AsRef<[u8]> for String<A>
+where
+    A: Unsize<[u8]>,
+{
+    #[inline]
+    fn as_ref(&self) -> &[u8] {
+        self.as_bytes()
+    }
+}
+
 impl<A, B> PartialEq<String<B>> for String<A>
 where
     A: Unsize<[u8]>,
diff --git a/src/vec.rs b/src/vec.rs
index 8dd4266e..79e387db 100644
--- a/src/vec.rs
+++ b/src/vec.rs
@@ -243,6 +243,46 @@ where
     }
 }
 
+impl<T, A> AsRef<Vec<T, A>> for Vec<T, A>
+where
+    A: Unsize<[T]>,
+{
+    #[inline]
+    fn as_ref(&self) -> &Vec<T, A> {
+        self
+    }
+}
+
+impl<T, A> AsMut<Vec<T, A>> for Vec<T, A>
+where
+    A: Unsize<[T]>,
+{
+    #[inline]
+    fn as_mut(&mut self) -> &mut Vec<T, A> {
+        self
+    }
+}
+
+impl<T, A> AsRef<[T]> for Vec<T, A>
+where
+    A: Unsize<[T]>,
+{
+    #[inline]
+    fn as_ref(&self) -> &[T] {
+        self
+    }
+}
+
+impl<T, A> AsMut<[T]> for Vec<T, A>
+where
+    A: Unsize<[T]>,
+{
+    #[inline]
+    fn as_mut(&mut self) -> &mut [T] {
+        self
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use Vec;