tests/ui/pattern/usefulness/match-arm-statics.rs

   1 #![allow(dead_code)]
   2 #![deny(unreachable_patterns)]
   3
   4 use self::Direction::{North, East, South, West};
   5
   6 #[derive(PartialEq, Eq)]
   7 struct NewBool(bool);
   8
   9 #[derive(PartialEq, Eq)]
  10 enum Direction {
  11     North,
  12     East,
  13     South,
  14     West
  15 }
  16
  17 const TRUE_TRUE: (bool, bool) = (true, true);
  18
  19 fn unreachable_1() {
  20     match (true, false) {
  21         TRUE_TRUE => (),
  22         (false, false) => (),
  23         (false, true) => (),
  24         (true, false) => (),
  25         (true, true) => ()
  26         //~^ ERROR unreachable pattern
  27     }
  28 }
  29
  30 const NONE: Option<Direction> = None;
  31 const EAST: Direction = East;
  32
  33 fn unreachable_2() {
  34     match Some(Some(North)) {
  35         Some(NONE) => (),
  36         Some(Some(North)) => (),
  37         Some(Some(EAST)) => (),
  38         Some(Some(South)) => (),
  39         Some(Some(West)) => (),
  40         Some(Some(East)) => (),
  41         //~^ ERROR unreachable pattern
  42         None => ()
  43     }
  44 }
  45
  46 const NEW_FALSE: NewBool = NewBool(false);
  47 struct Foo {
  48     bar: Option<Direction>,
  49     baz: NewBool
  50 }
  51
  52 fn unreachable_3() {
  53     match (Foo { bar: Some(EAST), baz: NewBool(true) }) {
  54         Foo { bar: None, baz: NewBool(true) } => (),
  55         Foo { bar: _, baz: NEW_FALSE } => (),
  56         Foo { bar: Some(West), baz: NewBool(true) } => (),
  57         Foo { bar: Some(South), .. } => (),
  58         Foo { bar: Some(EAST), .. } => (),
  59         Foo { bar: Some(North), baz: NewBool(true) } => (),
  60         Foo { bar: Some(EAST), baz: NewBool(false) } => ()
  61         //~^ ERROR unreachable pattern
  62     }
  63 }
  64
  65 fn main() {
  66     unreachable_1();
  67     unreachable_2();
  68     unreachable_3();
  69 }