Following code has borrow problem:
#[test]
fn main() {
let vec0 = vec![22, 44, 66];
let vec1 = fill_vec(vec0);
assert_eq!(vec0, vec![22, 44, 66]);
assert_eq!(vec1, vec![22, 44, 66, 88]);
}
fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
let mut vec = vec;
vec.push(88);
vec
}
⚠️ Compiling of exercises/move_semantics/move_semantics2.rs failed! Please try again. Here's the output:
error[E0382]: borrow of moved value: `vec0`
--> exercises/move_semantics/move_semantics2.rs:16:5
|
12 | let vec0 = vec![22, 44, 66];
| ---- move occurs because `vec0` has type `Vec<i32>`, which does not implement the `Copy` trait
13 |
14 | let vec1 = fill_vec(vec0);
| ---- value moved here
15 |
16 | assert_eq!(vec0, vec![22, 44, 66]);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ value borrowed here after move
|
note: consider changing this parameter type in function `fill_vec` to borrow instead if owning the value isn't necessary
--> exercises/move_semantics/move_semantics2.rs:20:18
|
20 | fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
| -------- ^^^^^^^^ this parameter takes ownership of the value
| |
| in this function
= note: this error originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
help: consider cloning the value if the performance cost is acceptable
|
14 | let vec1 = fill_vec(vec0.clone());
| ++++++++
error: aborting due to previous error
For more information about this error, try `rustc --explain E0382`.
Follow the suggestion, we can use clone()
:
let vec1 = fill_vec(vec0.clone());
标签:move,value,let,Cloning,vec0,fill,Rust,vec From: https://www.cnblogs.com/Answer1215/p/18036984