相关疑难解决方法(0)

我想将*mut指针转换为&mut引用。

// Both setting a value to ptr and getting a value from ptr succeeds.
let ptr: &mut usize = unsafe { &mut *(VIRTUAL_ADDRESS_TO_ACCESS_FREE_PAGE as *mut usize) };

这有效。但是，如果&mut在unsafe块之外，代码将无法部分工作。*ptr = foo不会存储foo到内存ptr点，但let foo = *ptr会将值分配*ptr给foo。

// Setting a value to ptr fails, but getting a value from ptr succeeds.
let ptr: &mut usize = &mut unsafe { *(VIRTUAL_ADDRESS_TO_ACCESS_FREE_PAGE as *mut usize) …

从Rust库中读取文档时遇到了这段代码：

for (ent, pos, vel) in (&*entities, &mut pos_storage, &vel_storage).join() {
    println!("Processing entity: {:?}", ent);
    *pos += *vel;
}

原始链接：https : //slide-rs.github.io/specs/08_join.html

＆*实体在这里做什么。据我所知，它是在取消引用实体，然后再次引用它？