You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: weak_ref_count.rs
    path of file: ./repos/windows-rs/crates/libs/core/src/imp
    
    the code of the file until where you have to start completion: use super::*;
use crate::Interface;
use std::sync::atomic::{AtomicIsize, Ordering};

#[doc(hidden)]
#[repr(transparent)]
#[derive(Default)]
pub struct WeakRefCount(AtomicIsize);

impl WeakRefCount {
    pub fn new() -> Self {
        Self(AtomicIsize::new(1))
    }

    pub f
    
    unsafe extern "system" fn StrongDowngrade(ptr: *mut std::ffi::c_void, interface: *mut *mut std::ffi::c_void) -> crate::HRESULT {
        let this = Self::from_strong_ptr(ptr);

        // The strong vtable hands out a reference to the weak vtable. This is always safe and
        // straightforward since a strong reference guarantees there is at least one weak
        // reference.
        *interface = &mut this.weak_vtable as *mut _ as _;
        this.weak_count.add_ref();
        crate::HRESULT(0)
    }