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: arc.rs
    path of file: ./repos/rslint/crates/rslint_rowan/src
    
    the code of the file until where you have to start completion: use nodrop::NoDrop;
use stable_deref_trait::{CloneStableDeref, StableDeref};
use std::borrow;
use std::cmp::Ordering;
use std::convert::From;
use std::fmt;
use std::hash::{Hash, Hasher};
use std::iter::{ExactSizeIterator, Iterator};
use std::mem;
use std::ops::{Deref, DerefMut};
use std::os::raw::c_void;
use std::process;
use std::ptr;
use std::slice;
use std
    
    pub fn make_mut(this: &mut Self) -> &mut T {
        if !this.is_unique() {
            // Another pointer exists; clone
            *this = Arc::new((**this).clone());
        }

        unsafe {
            // This unsafety is ok because we're guaranteed that the pointer
            // returned is the *only* pointer that will ever be returned to T. Our
            // reference count is guaranteed to be 1 at this point, and we required
            // the Arc itself to be `mut`, so we're returning the only possible
            // reference to the inner data.
            &mut (*this.ptr()).data
        }
    }