src/librustc_error_codes/error_codes/E0642.md

   1 Trait methods currently cannot take patterns as arguments.
   2
   3 Example of erroneous code:
   4
   5 ```compile_fail,E0642
   6 trait Foo {
   7     fn foo((x, y): (i32, i32)); // error: patterns aren't allowed
   8                                 //        in trait methods
   9 }
  10 ```
  11
  12 You can instead use a single name for the argument:
  13
  14 ```
  15 trait Foo {
  16     fn foo(x_and_y: (i32, i32)); // ok!
  17 }
  18 ```