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: vrc.rs
    path of file: ./repos/slint/helper_crates/vtable/src
    
    the code of the file until where you have to start completion: // Copyright © SixtyFPS GmbH <info@slint.dev>
// SPDX-License-Identifier: MIT OR Apache-2.0

// cSpell: ignore pointee repr

//! implementation of vtable::Vrc

use super::*;
use portable_atomic::{AtomicU32, Ordering};

/// This trait is implemented by the [`#[vtable]`](macro@vtable) macro.
///
/// It is implemented if the macro has a "drop_in_place" function.
///
/// # Safety
///
/// The implementation of drop_in_place and dealloc must be correct
pub unsafe trait VTableMetaDropInPlace: VTableM
    
    fn drop(&mut self) {
        unsafe {
            let inner = self.inner.as_ptr();
            if (*inner).strong_ref.fetch_sub(1, Ordering::SeqCst) == 1 {
                let data =
                    (inner as *mut u8).add(*core::ptr::addr_of!((*inner).data_offset) as usize);
                let vtable = core::ptr::addr_of!((*inner).vtable);
                let mut layout = VTable::drop_in_place(*vtable, data);
                layout = core::alloc::Layout::new::<VRcInner<VTable, ()>>()
                    .extend(layout.try_into().unwrap())
                    .unwrap()
                    .0
                    .pad_to_align()
                    .into();
                if (*core::ptr::addr_of!((*inner).weak_ref)).load(Ordering::SeqCst) > 1 {
                    // at this point we are sure that no other thread can access the data
                    // since we still hold a weak reference, so the other weak references
                    // in other thread won't start destroying the object.
                    *(VRcInner::data_ptr(self.inner.cast::<VRcInner<VTable, Layout>>().as_ptr())
                        as *mut Layout) = layout;
                }
                if (*core::ptr::addr_of!((*inner).weak_ref)).fetch_sub(1, Ordering::SeqCst) == 1 {
                    VTable::dealloc(*vtable, self.inner.cast().as_ptr(), layout);
                }
            }
        }
    }