Implement CoerceUnsized for {Cell, RefCell, UnsafeCell}

This commit is contained in:
Andrew Paseltiner 2016-08-12 18:10:34 -04:00
parent 13ff307f07
commit 1fd791ad62
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@ -337,6 +337,9 @@ impl<T: Copy> From<T> for Cell<T> {
}
}
#[unstable(feature = "coerce_unsized", issue = "27732")]
impl<T: CoerceUnsized<U>, U> CoerceUnsized<Cell<U>> for Cell<T> {}
/// A mutable memory location with dynamically checked borrow rules
///
/// See the [module-level documentation](index.html) for more.
@ -757,6 +760,9 @@ impl<T> From<T> for RefCell<T> {
}
}
#[unstable(feature = "coerce_unsized", issue = "27732")]
impl<T: CoerceUnsized<U>, U> CoerceUnsized<RefCell<U>> for RefCell<T> {}
struct BorrowRef<'b> {
borrow: &'b Cell<BorrowFlag>,
}
@ -1086,3 +1092,13 @@ impl<T> From<T> for UnsafeCell<T> {
UnsafeCell::new(t)
}
}
#[unstable(feature = "coerce_unsized", issue = "27732")]
impl<T: CoerceUnsized<U>, U> CoerceUnsized<UnsafeCell<U>> for UnsafeCell<T> {}
#[allow(unused)]
fn assert_coerce_unsized(a: UnsafeCell<&i32>, b: Cell<&i32>, c: RefCell<&i32>) {
let _: UnsafeCell<&Send> = a;
let _: Cell<&Send> = b;
let _: RefCell<&Send> = c;
}