rust - 在循环中/分配: expected type parameter `T` ,找到了 `&T`

Question

error on playground

enum Error {}

fn foo<T>(bars: Vec<T>) -> Result<Vec<T>, Error>
{
    let mut baz = vec![];
    for bar in bars.iter(){
            baz.push(bar);
    }
    Ok(baz)
}

像＆或*这样的东西似乎无法解决，也因为 bar是外部包装箱

enum Error {}

fn foo<T>(bars: Vec<T>) -> Result<Vec<T>, Error>
{
    let mut baz = vec![];
    for &bar in bars.iter(){
            baz.push(bar);
    }
    Ok(*baz)
}

是什么原因引起的？它将如何运作？

Answer 1

solution in playground
问题是，.iter()总是返回引用值。
the reference显示以下内容:

There are three common methods which can create iterators from a collection:

    iter(), which iterates over &T.
    iter_mut(), which iterates over &mut T.
    into_iter(), which iterates over T.

enum Error {}

fn foo<T>(bars: Vec<T>) -> Result<Vec<T>, Error>
{
    let mut baz = vec![];
    for bar in bars.into_iter(){
            baz.push(bar);
    }
    Ok(baz)
}