Role reader was created as a mutable role. It is recommended to make this role immutable, which will become the default behavior of the bootstrap command in the future.You can opt into this behavior by using the --immutable-role flag, or update role reader with the 'immutable' resource option.这个日志是啥意思
时间: 2023-06-01 10:01:35 浏览: 60
这个日志是关于角色 "reader" 的提示,建议将其设置为不可变的角色。在将来的版本中,这将成为 "bootstrap" 命令的默认行为。您可以使用 "--immutable-role" 标志来选择这种行为,或者使用 "immutable" 资源选项来更新 "reader" 角色。
相关问题
rust cannot move out of `self.root` as enum variant `Some` which is behind a mutable reference
This error occurs when trying to move a value out of a borrowed mutable reference. In Rust, borrowing a value as mutable means that it cannot be moved out of the reference until the reference goes out of scope.
In this specific case, the error message is indicating that the code is trying to move the value of `self.root` out of a mutable reference to an `Option` variant `Some`. This is not allowed because `Some` is a non-trivial value that cannot be copied, and moving it out of the reference would leave the mutable reference in an invalid state.
To fix this error, the code needs to be modified to ensure that the value of `self.root` is not moved out of the mutable reference. One possible solution is to use the `take` method on the `Option` type, which replaces the value with `None` and returns the original value, allowing it to be moved out of the reference safely:
```rust
let root = self.root.take().unwrap();
```
This code first calls `take` on `self.root` to replace the value with `None` and return the original value. Then, it uses `unwrap` to extract the value from the `Option` variant `Some` and move it out of the reference. Since `self.root` is now `None`, the mutable reference is still valid and can be used for further operations.
react-dom.development.js:1680 Warning: Failed prop type: You provided a `value` prop to a form field without an `onChange` handler. This will render a read-only field. If the field should be mutable use `defaultValue`. Otherwise, set either `onChange` or `readOnly`. in input (created by Hello) in Hello
这个警告提示你在一个表单字段上提供了 `value` 属性,但是没有提供 `onChange` 处理函数。这样会导致该字段只读,如果该字段应该是可变的,请使用 `defaultValue`。否则,请设置 `onChange` 或 `readOnly` 属性。在你的代码中,你需要为这个表单字段提供一个 `onChange` 处理函数来处理用户输入的变化。例如:
```
class Hello extends React.Component {
constructor(props) {
super(props);
this.state = { value: '' };
this.handleChange = this.handleChange.bind(this);
}
handleChange(event) {
this.setState({ value: event.target.value });
}
render() {
return (
<form>
<label>
Name:
<input type="text" value={this.state.value} onChange={this.handleChange} />
</label>
</form>
);
}
}
```
在这个例子中,我们为 `input` 元素提供了一个 `onChange` 处理函数 `handleChange`,它会更新组件状态中的 `value` 属性。这样就可以避免这个警告了。