为什么我的 TryFrom<Vec<T>> 实现没有涵盖 TryFrom<Vec<String>>?
Why doesn't my implementation of TryFrom<Vec<T>> cover TryFrom<Vec<String>>?
当我尝试编译此行时,opt.positionals = Positionals::try_from(opt.args).unwrap();
我收到有关未实现特征的错误。这个特性应该像我一样 TryFrom<Vec<T>>
这里是错误,
error[E0277]: the trait bound `Positionals: TryFrom<Vec<String>>` is not satisfied
--> bin/seq.rs:83:20
|
83 | opt.positionals = Positionals::try_from(opt.args).unwrap();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `TryFrom<Vec<String>>` is not implemented for `Positionals`
|
= help: the following implementations were found:
<Positionals as TryFrom<Vec<T>>>
这是我对特征的实现,
use std::convert::TryFrom;
impl<T: Debug + AsRef<String> + Into<String> + Clone> TryFrom<Vec<T>> for Positionals {
为什么我的 TryFrom<Vec<T>>
实施没有涵盖具体 TryFrom<Vec<String>>
,我该如何解决这个问题?
String
未实现 AsRef<String>
。您可以改用 AsRef<str>
或 Borrow<String>
。
当我尝试编译此行时,opt.positionals = Positionals::try_from(opt.args).unwrap();
我收到有关未实现特征的错误。这个特性应该像我一样 TryFrom<Vec<T>>
这里是错误,
error[E0277]: the trait bound `Positionals: TryFrom<Vec<String>>` is not satisfied
--> bin/seq.rs:83:20
|
83 | opt.positionals = Positionals::try_from(opt.args).unwrap();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `TryFrom<Vec<String>>` is not implemented for `Positionals`
|
= help: the following implementations were found:
<Positionals as TryFrom<Vec<T>>>
这是我对特征的实现,
use std::convert::TryFrom;
impl<T: Debug + AsRef<String> + Into<String> + Clone> TryFrom<Vec<T>> for Positionals {
为什么我的 TryFrom<Vec<T>>
实施没有涵盖具体 TryFrom<Vec<String>>
,我该如何解决这个问题?
String
未实现 AsRef<String>
。您可以改用 AsRef<str>
或 Borrow<String>
。