src/librustc_error_codes/error_codes/E0399.md

   1 #### Note: this error code is no longer emitted by the compiler
   2
   3 You implemented a trait, overriding one or more of its associated types but did
   4 not reimplement its default methods.
   5
   6 Example of erroneous code:
   7
   8 ```
   9 #![feature(associated_type_defaults)]
  10
  11 pub trait Foo {
  12     type Assoc = u8;
  13     fn bar(&self) {}
  14 }
  15
  16 impl Foo for i32 {
  17     // error - the following trait items need to be reimplemented as
  18     //         `Assoc` was overridden: `bar`
  19     type Assoc = i32;
  20 }
  21 ```
  22
  23 To fix this, add an implementation for each default method from the trait:
  24
  25 ```
  26 #![feature(associated_type_defaults)]
  27
  28 pub trait Foo {
  29     type Assoc = u8;
  30     fn bar(&self) {}
  31 }
  32
  33 impl Foo for i32 {
  34     type Assoc = i32;
  35     fn bar(&self) {} // ok!
  36 }
  37 ```