Rust的Copy和Clone

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#[derive(Debug)]
#[allow(unused)]
struct User {
    age: i32
}

fn main() {
    let u: User = User{
        age: 25
    };
    println!("{:?}",u);
    let another_u = u;
    println!("{:?}",u);
}

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error[E0382]: borrow of moved value: `u`
  --> src\main.rs:13:21
   |
8  |     let u: User = User{
   |         - move occurs because `u` has type `User`, which does not implement the `Copy` trait
...
12 |     let another_u = u;
   |                     - value moved here
13 |     println!("{:?}",u);
   |                     ^ value borrowed here after move
   |
note: if `User` implemented `Clone`, you could clone the value
  --> src\main.rs:3:1
   |
3  | struct User {
   | ^^^^^^^^^^^ consider implementing `Clone` for this type
...
12 |     let another_u = u;
   |                     - you could clone this value
   = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)

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#[derive(Debug,Clone)]
#[allow(unused)]
struct User {
    age: i32
}

fn main() {
    let u: User = User{
        age: 25
    };
    println!("{:?}",u);
    let another_u = u.clone();
    println!("{:?}",u);
    println!("{:?}",another_u);
}

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#[derive(Debug,Clone,Copy)]
#[allow(unused)]
struct User {
    age: i32
}

fn main() {
    let u: User = User{
        age: 25
    };
    println!("{:?}",u);
    let another_u = u;
    println!("{:?}",u);
    println!("{:?}",another_u);
}