src/librustc_error_codes/error_codes/E0186.md

   1 An associated function for a trait was defined to be a method (i.e., to take a
   2 `self` parameter), but an implementation of the trait declared the same function
   3 to be static.
   4
   5 Erroneous code example:
   6
   7 ```compile_fail,E0186
   8 trait Foo {
   9     fn foo(&self);
  10 }
  11
  12 struct Bar;
  13
  14 impl Foo for Bar {
  15     // error, method `foo` has a `&self` declaration in the trait, but not in
  16     // the impl
  17     fn foo() {}
  18 }
  19 ```
  20
  21 When a type implements a trait's associated function, it has to use the same
  22 signature. So in this case, since `Foo::foo` takes `self` as argument and
  23 does not return anything, its implementation on `Bar` should be the same:
  24
  25 ```
  26 trait Foo {
  27     fn foo(&self);
  28 }
  29
  30 struct Bar;
  31
  32 impl Foo for Bar {
  33     fn foo(&self) {} // ok!
  34 }
  35 ```