#[test]
fn test_ptr() {
    #[derive(Debug)]
    struct Foo{
        a:i32
    }

    impl Pointer for Foo {
        fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
            let ptr = self as *const Self;
            ptr.fmt(f)
        }
    }

    let mut f1 = Foo{a:10};
    unsafe {
        let f2 = ptr::read(&f1);
        println!("{:p}", f1);
        println!("{:p}", f2);
    }
}

为什么打印的两个指针不一样