《Deref 解引用》章节错误

在《Deref 解引用》章节出现错误：

在这里，返回 *self，应该是错误的，假设 Self 是 &T，而 &self 就是 &Self，也就是&&T。此时返回self才对，也就是 返回 &T。而返回 *self 就是返回T了。

而在标准库中就是

#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_convert", issue = "143773")]
impl<T: ?Sized> const Deref for &T {
    type Target = T;

    #[rustc_diagnostic_item = "noop_method_deref"]
    fn deref(&self) -> &T {
        self
    }
}

#[stable(feature = "rust1", since = "1.0.0")]
impl<T: ?Sized> !DerefMut for &T {}

#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_convert", issue = "143773")]
impl<T: ?Sized> const Deref for &mut T {
    type Target = T;

    fn deref(&self) -> &T {
        self
    }
}