我遇到了一个错误:
extern crate rustc_serialize; // 0.3.24
use rustc_serialize::base64::{self, FromBase64, ToBase64};
fn main() {
let a: [u8; 30] = [0; 30];
let b = a.from_base64().unwrap().as_slice();
println!("{:?}", b);
}
错误:
error[E0597]: borrowed value does not live long enough
--> src/main.rs:7:13
|
7 | let b = a.from_base64().unwrap().as_slice();
| ^^^^^^^^^^^^^^^^^^^^^^^^ - temporary value dropped here while still borrowed
| |
| temporary value does not live long enough
8 | println!("{:?}", b);
9 | }
| - temporary value needs to live until here
|
= note: consider using a `let` binding to increase its lifetime
对我来说,代码没有错。为什么我有这个错误?
答案 0 :(得分:16)
这里的问题是你没有将from_base64
的结果存储在任何地方,然后通过调用as_slice
来引用它。链接这样的调用会导致from_base64
的结果超出行尾的范围,并且所引用的引用不再有效。
extern crate rustc_serialize; // 0.3.24
use rustc_serialize::base64::FromBase64;
fn main() {
let a: [u8; 30] = [0; 30];
let b = a.from_base64().unwrap();
println!("{:?}", b.as_slice());
}