发生移动是因为 value 的类型为 Vec，它没有实现 `Copy` 特征

我正在编写一个非常简单的递归程序，用于查找两个数字之间的所有素数：

use std::cmp::PartialOrd;
use std::ops::{Add, Div, Rem, Sub};

fn _is_prime<T>(n: T, dividend: T, one: T) -> bool
where
    T: Copy + Rem<Output = T> + Sub<Output = T> + PartialOrd,
{
    if dividend == one {
        true
    } else {
        if n % dividend < one {
            false
        } else {
            _is_prime(n, dividend - one, one)
        }
    }
}

fn _primes_between<'a, T>(a: T, b: T, one: T, v: &'a mut Vec<T>) -> &'a mut Vec<T>
where
    T: Copy + Rem<Output = T> + Add<Output = T> + Sub<Output = T> + PartialOrd,
{
    if a <= b {
        if _is_prime(a, a - one, one) {
            v.push(a);
        }

        _primes_between(a + one, b, one, v)
    } else {
        v
    }
}

fn primes_between<T>(a: T, b: T) -> Vec<T>
where
    T: Copy + Div<Output = T> + Rem<Output = T> + Add<Output = T> + Sub<Output = T> + PartialOrd,
{
    let one = a / a;

    let mut v: Vec<T> = Vec::new();

    *_primes_between(a, b, one, &mut v)
}

fn main() {
    primes_between(3, 13).iter().for_each(|i| println!("{}", i));
}

问题是：

error[E0507]: cannot move out of a mutable reference
  --> src/main.rs:42:5
   |
42 |     *_primes_between(a, b, one, &mut v)
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ move occurs because value has type `std::vec::Vec<T>`, which does not implement the `Copy` trait

我该如何解决该错误？

我不是 100% 确定，但我认为问题在于_primes_between()返回第 31 行代码尝试复制的引用。 （通过取得所有权*操作员）您可以通过致电解决问题.clone()关于结果，但我认为在这种情况下你不需要_primes_between()返回一个值 - 您只需将适当的条目添加到v参数代替。就像是

fn _primes_between<T>(a: T, b: T, one: T, v: &mut Vec<T>)
where
    T: Copy + Rem<Output = T> + Add<Output = T> + Sub<Output = T> + PartialOrd,
{
    if a <= b {
        if _is_prime(a, a - one, one) {
            v.push(a);
        }

        _primes_between(a + one, b, one, v);
    }
}

fn primes_between<T>(a: T, b: T) -> Vec<T>
where
    T: Copy + Div<Output = T> + Rem<Output = T> + Add<Output = T> + Sub<Output = T> + PartialOrd,
{
    let one = a / a;

    let mut v: Vec<T> = Vec::new();

    _primes_between(a, b, one, &mut v);

    v
}