Method clone

src/rc/weak.rs:43–49

(&self)

impl Clone for WeakPtr {
    fn clone(&self) -> Self {
        let ptr = Box::new(UnsafeCell::new(ptr::null_mut()));
        unsafe {
            runtime::objc_copyWeak(ptr.get(), self.0.get());
        }
        WeakPtr(ptr)
    }
}