use fmt::{self, Debug, Display};
use marker::Unsize;
use mem;
-use ops::{Deref, DerefMut, CoerceUnsized};
+use ops::{Deref, DerefMut, CoerceUnsized, Index};
use ptr;
+use slice::SliceIndex;
/// A mutable memory location.
///
///
/// let slice: &mut [i32] = &mut [1, 2, 3];
/// let cell_slice: &Cell<[i32]> = Cell::from_mut(slice);
- /// assert_eq!(cell_slice.len(), 3);
+ /// assert_eq!(cell_slice[..].len(), 3);
///
/// let slice_cell: &[Cell<i32>] = &cell_slice[..];
/// assert_eq!(slice_cell.len(), 3);
impl<T: CoerceUnsized<U>, U> CoerceUnsized<Cell<U>> for Cell<T> {}
#[unstable(feature = "as_cell", issue="43038")]
-impl<T> Deref for Cell<[T]> {
- type Target = [Cell<T>];
+impl<T, I> Index<I> for Cell<[T]>
+ where I: SliceIndex<[Cell<T>]>
+{
+ type Output = I::Output;
- #[inline]
- fn deref(&self) -> &[Cell<T>] {
- unsafe {
- &*(self as *const Cell<[T]> as *const [Cell<T>])
- }
- }
-}
-
-#[unstable(feature = "as_cell", issue="43038")]
-impl<T> DerefMut for Cell<[T]> {
- #[inline]
- fn deref_mut(&mut self) -> &mut [Cell<T>] {
+ fn index(&self, index: I) -> &Self::Output {
unsafe {
- &mut *(self as *mut Cell<[T]> as *mut [Cell<T>])
+ Index::index(&*(self as *const Cell<[T]> as *const [Cell<T>]), index)
}
}
}
fn main() {
let slice: &mut [i32] = &mut [1, 2, 3];
let cell_slice: &Cell<[i32]> = Cell::from_mut(slice);
- assert_eq!(cell_slice.len(), 3);
+ assert_eq!(cell_slice[..].len(), 3);
let sub_slice: &[Cell<i32>] = &cell_slice[1..];
assert_eq!(sub_slice.len(), 2);