src/test/ui/rfc-2008-non-exhaustive/enum.rs

   1 // aux-build:enums.rs
   2 extern crate enums;
   3
   4 use enums::{EmptyNonExhaustiveEnum, NonExhaustiveEnum};
   5
   6 fn empty(x: EmptyNonExhaustiveEnum) {
   7     match x {} //~ ERROR type `enums::EmptyNonExhaustiveEnum` is non-empty
   8     match x {
   9         _ => {}, // ok
  10     }
  11 }
  12
  13 fn main() {
  14     let enum_unit = NonExhaustiveEnum::Unit;
  15
  16     match enum_unit {
  17         //~^ ERROR non-exhaustive patterns: `_` not covered [E0004]
  18         NonExhaustiveEnum::Unit => "first",
  19         NonExhaustiveEnum::Tuple(_) => "second",
  20         NonExhaustiveEnum::Struct { .. } => "third"
  21     };
  22
  23     match enum_unit {};
  24     //~^ ERROR non-exhaustive patterns: `_` not covered [E0004]
  25
  26     // Everything below this is expected to compile successfully.
  27
  28     let enum_unit = NonExhaustiveEnum::Unit;
  29
  30     match enum_unit {
  31         NonExhaustiveEnum::Unit => 1,
  32         NonExhaustiveEnum::Tuple(_) => 2,
  33         // This particular arm tests that a enum marked as non-exhaustive
  34         // will not error if its variants are matched exhaustively.
  35         NonExhaustiveEnum::Struct { field } => field,
  36         _ => 0 // no error with wildcard
  37     };
  38
  39     match enum_unit {
  40         _ => "no error with only wildcard"
  41     };
  42
  43     // #53549: Check that variant constructors can still be called normally.
  44     match NonExhaustiveEnum::Unit {
  45         NonExhaustiveEnum::Unit => {},
  46         _ => {}
  47     };
  48
  49     match NonExhaustiveEnum::Tuple(2) {
  50         NonExhaustiveEnum::Tuple(2) => {},
  51         _ => {}
  52     };
  53
  54     match (NonExhaustiveEnum::Unit {}) {
  55         NonExhaustiveEnum::Unit {} => {},
  56         _ => {}
  57     };
  58
  59     match (NonExhaustiveEnum::Tuple { 0: 2 }) {
  60         NonExhaustiveEnum::Tuple { 0: 2 } => {},
  61         _ => {}
  62     };
  63
  64     match (NonExhaustiveEnum::Struct { field: 2 }) {
  65         NonExhaustiveEnum::Struct { field: 2 } => {},
  66         _ => {}
  67     };
  68
  69 }