src/librustc_error_codes/error_codes/E0283.md

   1 This error occurs when the compiler doesn't have enough information
   2 to unambiguously choose an implementation.
   3
   4 For example:
   5
   6 ```compile_fail,E0283
   7 trait Generator {
   8     fn create() -> u32;
   9 }
  10
  11 struct Impl;
  12
  13 impl Generator for Impl {
  14     fn create() -> u32 { 1 }
  15 }
  16
  17 struct AnotherImpl;
  18
  19 impl Generator for AnotherImpl {
  20     fn create() -> u32 { 2 }
  21 }
  22
  23 fn main() {
  24     let cont: u32 = Generator::create();
  25     // error, impossible to choose one of Generator trait implementation
  26     // Should it be Impl or AnotherImpl, maybe something else?
  27 }
  28 ```
  29
  30 To resolve this error use the concrete type:
  31
  32 ```
  33 trait Generator {
  34     fn create() -> u32;
  35 }
  36
  37 struct AnotherImpl;
  38
  39 impl Generator for AnotherImpl {
  40     fn create() -> u32 { 2 }
  41 }
  42
  43 fn main() {
  44     let gen1 = AnotherImpl::create();
  45
  46     // if there are multiple methods with same name (different traits)
  47     let gen2 = <AnotherImpl as Generator>::create();
  48 }
  49 ```