New upstream version 1.64.0+dfsg1

[rustc.git] / compiler / rustc_error_codes / src / error_codes / E0118.md

An inherent implementation was defined for something which isn't a struct,
enum, union, or trait object.

Erroneous code example:

```compile_fail,E0118
impl<T> T { // error: no nominal type found for inherent implementation
    fn get_state(&self) -> String {
        // ...
    }
}
```

To fix this error, please implement a trait on the type or wrap it in a struct.
Example:

```
// we create a trait here
trait LiveLongAndProsper {
    fn get_state(&self) -> String;
}

// and now you can implement it on T
impl<T> LiveLongAndProsper for T {
    fn get_state(&self) -> String {
        "He's dead, Jim!".to_owned()
    }
}
```

Alternatively, you can create a newtype. A newtype is a wrapping tuple-struct.
For example, `NewType` is a newtype over `Foo` in `struct NewType(Foo)`.
Example:

```
struct TypeWrapper<T>(T);

impl<T> TypeWrapper<T> {
    fn get_state(&self) -> String {
        "Fascinating!".to_owned()
    }
}
```