显示原始指针

Rust 有一个指针类型的默认格式化程序，可用于显示指针。

use std::ptr;

// Create some data, a raw pointer pointing to it and a null pointer
let data: u32 = 42;
let raw_ptr = &data as *const u32;
let null_ptr = ptr::null() as *const u32;

// the {:p} mapping shows pointer values as hexadecimal memory addresses
println!("Data address: {:p}", &data);
println!("Raw pointer address: {:p}", raw_ptr); 
println!("Null pointer address: {:p}", null_ptr);

这将输出如下内容：

Data address: 0x7fff59f6bcc0
Raw pointer address: 0x7fff59f6bcc0
Null pointer address: 0x0