src/librustc_error_codes/error_codes/E0069.md

   1 The compiler found a function whose body contains a `return;` statement but
   2 whose return type is not `()`.
   3
   4 Erroneous code example:
   5
   6 ```compile_fail,E0069
   7 // error
   8 fn foo() -> u8 {
   9     return;
  10 }
  11 ```
  12
  13 Since `return;` is just like `return ();`, there is a mismatch between the
  14 function's return type and the value being returned.