///
/// # Safety
///
- /// Any other `Rc` or [`Weak`] pointers to the same allocation must not be dereferenced
- /// for the duration of the returned borrow.
- /// This is trivially the case if no such pointers exist,
- /// for example immediately after `Rc::new`.
+ /// If any other `Rc` or [`Weak`] pointers to the same allocation exist, then
+ /// they must be must not be dereferenced or have active borrows for the duration
+ /// of the returned borrow, and their inner type must be exactly the same as the
+ /// inner type of this Rc (including lifetimes). This is trivially the case if no
+ /// such pointers exist, for example immediately after `Rc::new`.
///
/// # Examples
///
///
/// # Safety
///
- /// Any other `Arc` or [`Weak`] pointers to the same allocation must not be dereferenced
- /// for the duration of the returned borrow.
- /// This is trivially the case if no such pointers exist,
- /// for example immediately after `Arc::new`.
+ /// If any other `Arc` or [`Weak`] pointers to the same allocation exist, then
+ /// they must be must not be dereferenced or have active borrows for the duration
+ /// of the returned borrow, and their inner type must be exactly the same as the
+ /// inner type of this Rc (including lifetimes). This is trivially the case if no
+ /// such pointers exist, for example immediately after `Arc::new`.
///
/// # Examples
///