pub type DowngradeIntoFn = for<'ptr> unsafe fn(PtrMut<'ptr>, PtrUninit<'ptr>) -> PtrMut<'ptr>;Expand description
Downgrades a strong pointer to a weak one.
Initializes the smart 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 std::sync::Arc or std::rc::Rc).
ยงSafety
strong must be a valid strong smart pointer (like std::sync::Arc or std::rc::Rc).
weak must be allocated, and of the right layout for the corresponding weak pointer.
weak must not have been initialized yet.