compiler/rustc_error_codes/src/error_codes/E0165.md

   1 #### Note: this error code is no longer emitted by the compiler.
   2
   3 A while-let pattern attempts to match the pattern, and enters the body if the
   4 match was successful. If the match is irrefutable (when it cannot fail to
   5 match), use a regular `let`-binding inside a `loop` instead. For instance:
   6
   7 ```no_run
   8 struct Irrefutable(i32);
   9 let irr = Irrefutable(0);
  10
  11 // This fails to compile because the match is irrefutable.
  12 while let Irrefutable(x) = irr {
  13     // ...
  14 }
  15 ```
  16
  17 Try this instead:
  18
  19 ```no_run
  20 struct Irrefutable(i32);
  21 let irr = Irrefutable(0);
  22
  23 loop {
  24     let Irrefutable(x) = irr;
  25     // ...
  26 }
  27 ```