Rust 使用 HashMap 条目时如何避免字符串键的短暂克隆

我编写了以下工作代码:

#[derive(Debug, PartialEq, Serialize)]
struct Grid64Row {
    ...
    cell: String, 
    ...
}
...
    let mut rows_by_cell: HashMap::<String, Vec<Grid64Row>> = HashMap::new();
    for row in rows {
        match rows_by_cell.entry(row.cell.clone()) {
            Entry::Vacant(e) => { e.insert(vec![row]); },
            Entry::Occupied(mut e) => { e.get_mut().push(row); }
        }
    }

据我所知，我需要row.cell-String的clone()次.编译器同意，如果我删除.clone()，我会得到:

 error[E0382]: use of partially moved value: `row`
  --> foobar/src/main.rs:97:49
   |
96 |         match rows_by_cell.entry(row.cell) {
   |                                  -------- value partially moved here
97 |             Entry::Vacant(e) => { e.insert(vec![row]); },
   |                                                 ^^^ value used here after partial move
   |
   = note: partial move occurs because `row.cell` has type `std::string::String`, which does not implement the `Copy` trait

有没有办法解决这个短命的克隆？(我不明白为什么‘.entry()’需要String分，而不是&str分，但即使这样也会有借款问题.)