rust - structopt：错误[E0277]：特征绑定`String：From<&OsStr>`

Question

我正在使用 Rust 的structoptcrate，但是当我尝试编译示例时，出现以下错误，

error[E0277]: the trait bound `String: From<&OsStr>` is not satisfied
   --> bin/seq.rs:21:36
    |
21  |     #[structopt(short, long, parse(from_os_str))]
    |                                    ^^^^^^^^^^^ the trait `From<&OsStr>` is not implemented for `String`
    |
    = help: the following implementations were found:
              <String as From<&String>>
              <String as From<&mut str>>
              <String as From<&str>>
              <String as From<Box<str>>>
            and 2 others
note: required by `from`

Answer 1

您可以通过可靠的转换将 a 转换String为 aOsString，但不能将 a 转换OsString为 a String。

这是因为 anOsStr接受无效的东西，Strings因此无法确保解析为的 anOsStr可以structopt转换为String.

你可能根本不需要parse()，

#[structopt(short, long)]

不是

#[structopt(short, long, parse(from_os_str))]