compiler/rustc_error_codes/src/error_codes/E0118.md

   1 An inherent implementation was defined for something which isn't a struct,
   2 enum, union, or trait object.
   3
   4 Erroneous code example:
   5
   6 ```compile_fail,E0118
   7 impl<T> T { // error: no nominal type found for inherent implementation
   8     fn get_state(&self) -> String {
   9         // ...
  10     }
  11 }
  12 ```
  13
  14 To fix this error, please implement a trait on the type or wrap it in a struct.
  15 Example:
  16
  17 ```
  18 // we create a trait here
  19 trait LiveLongAndProsper {
  20     fn get_state(&self) -> String;
  21 }
  22
  23 // and now you can implement it on T
  24 impl<T> LiveLongAndProsper for T {
  25     fn get_state(&self) -> String {
  26         "He's dead, Jim!".to_owned()
  27     }
  28 }
  29 ```
  30
  31 Alternatively, you can create a newtype. A newtype is a wrapping tuple-struct.
  32 For example, `NewType` is a newtype over `Foo` in `struct NewType(Foo)`.
  33 Example:
  34
  35 ```
  36 struct TypeWrapper<T>(T);
  37
  38 impl<T> TypeWrapper<T> {
  39     fn get_state(&self) -> String {
  40         "Fascinating!".to_owned()
  41     }
  42 }
  43 ```