collections - 有什么方法可以允许移动具有借入元素但不能删除它的容器？

Question

我有这个容器:

use std::ptr::NonNull;

struct Container {
    data: NonNull<u8>,
}

impl Container {
    fn new() -> Container {
        todo!()
    }
    fn borrow_some_heap_data<'a>(&'a self) -> &'a u8 {
        todo!()
    }
    fn borrow_some_heap_data_mut<'a>(&'a mut self) -> &'a mut u8 {
        todo!()
    }
}

impl Drop for Container {
    fn drop(&mut self) {
        todo!()
    }
}

fn main() {
    let container = Container::new();
    let data = container.borrow_some_heap_data(); // or mut

    {
        let container = container; // move

        // This is safe because the move is a memcpy and the heap data doesn't change.
        println!("{}", *data);
    }

    // This is not safe because the container has been dropped
    // println!("{}", *data);
}

error[E0505]: cannot move out of `container` because it is borrowed
  --> src/main.rs:30:25
   |
27 |     let data = container.borrow_some_heap_data(); // or mut
   |                --------- borrow of `container` occurs here
...
30 |         let container = container; // move
   |                         ^^^^^^^^^ move out of `container` occurs here
...
33 |         println!("{}", *data);
   |                        ----- borrow later used here

即使有引用，移动容器也是安全的。但是，丢弃它是不安全的。有什么办法可以在Rust中表达这一点，允许移动，但不允许 drop？
直到删除该结构， data才会释放。

Answer 1

不，没有办法在安全的Rust中执行此操作；编译器不够智能/没有语法可以区分容器的生存期和元素的生存期。
从Why can't I store a value and a reference to that value in the same struct?:

There is a special case where the lifetime tracking is overzealous:when you have something placed on the heap. This occurs when you use aBox<T>, for example. In this case, the structure that is movedcontains a pointer into the heap. The pointed-at value will remainstable, but the address of the pointer itself will move. In practice,this doesn't matter, as you always follow the pointer.