?Sized bounds for rc::Weak::as_ptr and friends

This commit is contained in:
CAD97 2020-07-08 16:24:56 -04:00
parent 728938346b
commit 0c61ce2cf0

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@ -1721,7 +1721,21 @@ impl<T> Weak<T> {
pub fn new() -> Weak<T> {
Weak { ptr: NonNull::new(usize::MAX as *mut RcBox<T>).expect("MAX is not 0") }
}
}
pub(crate) fn is_dangling<T: ?Sized>(ptr: NonNull<T>) -> bool {
let address = ptr.as_ptr() as *mut () as usize;
address == usize::MAX
}
/// Helper type to allow accessing the reference counts without
/// making any assertions about the data field.
struct WeakInner<'a> {
weak: &'a Cell<usize>,
strong: &'a Cell<usize>,
}
impl<T: ?Sized> Weak<T> {
/// Returns a raw pointer to the object `T` pointed to by this `Weak<T>`.
///
/// The pointer is valid only if there are some strong references. The pointer may be dangling,
@ -1854,21 +1868,7 @@ impl<T> Weak<T> {
// SAFETY: we now have recovered the original Weak pointer, so can create the Weak.
Weak { ptr: unsafe { NonNull::new_unchecked(ptr) } }
}
}
pub(crate) fn is_dangling<T: ?Sized>(ptr: NonNull<T>) -> bool {
let address = ptr.as_ptr() as *mut () as usize;
address == usize::MAX
}
/// Helper type to allow accessing the reference counts without
/// making any assertions about the data field.
struct WeakInner<'a> {
weak: &'a Cell<usize>,
strong: &'a Cell<usize>,
}
impl<T: ?Sized> Weak<T> {
/// Attempts to upgrade the `Weak` pointer to an [`Rc`], delaying
/// dropping of the inner value if successful.
///