第 13 章 13.1.4节 解引用原生指针

[Kreedzt]

代码清单13-10

变量定义 address 超出范围

playground也报错: 链接

#![allow(unused)]
fn main() {
    let mut s = "hello".to_string();
    let r1 = &s as *const String;
    let r2 = &mut s as *mut String;
    assert_eq!(r1, r2);
    let address = 0x7fff1d72307d; // error: literal out of range for i32
    let r3 = address as *const String; 
    unsafe {
        println!("r1 is: {}", *r1);
       println!("r2 is: {}", *r2);
       // Segmentation fault  
       // assert_eq!(*r1, *r3)
   }
}

错误信息

error: literal out of range for i32
 --> src/main.rs:7:19
  |
7 |     let address = 0x7fff1d72307d;
  |                   ^^^^^^^^^^^^^^
  |
  = note: `#[deny(overflowing_literals)]` on by default
  = note: the literal `0x7fff1d72307d` (decimal `140733687410813`) does not fit into the type `i32` and will become `494022781i32`
  = help: consider using `i64` instead

声明为 u64 即可编译通过