pub type DowngradeIntoFn = unsafe fn(strong: PtrMut, weak: PtrUninit) -> PtrMut;Expand description
Downgrades a strong pointer to a weak one.
Initializes the pointer into the given weak, and returns a copy of weak, which has
been guaranteed to be initialized.
Only strong pointers can be downgraded (like alloc::sync::Arc or alloc::rc::Rc).
ยงSafety
strong must be a valid strong pointer (like alloc::sync::Arc or alloc::rc::Rc).
weak must be allocated, and of the right layout for the corresponding weak pointer.
weak must not have been initialized yet.