# E0263

An `impl Trait` method that the trait does not declare. Spans the method name.

**Machine-applicable fix:** none.

## Example

This program fails with `E0263`.

```oska
trait Shape {
    fn area(self) -> Int
}

struct Square { side: Int }

impl Shape for Square {
    fn area(self) -> Int {
        self.side * self.side
    }
    fn name(self) -> String {
        "square"
    }
}
```

## Fixed

The same program, fixed.

```oska
trait Shape {
    fn area(self) -> Int
}

struct Square { side: Int }

impl Shape for Square {
    fn area(self) -> Int {
        self.side * self.side
    }
}

impl Square {
    fn name(self) -> String {
        "square"
    }
}
```

Listed in the [checker notes](/checker.md#e0263). `oskac explain E0263` prints this entry offline.